Notice of 2024 Annual Meeting of Stockholders

2024 Annual General Meeting of Stockholders Details

We have adopted a virtual format for our 2024 Annual Meeting. In order to attend the Annual Meeting, you must register in advance at www.proxydocs.com/ACIW. Upon completing your registration, you will receive further instructions via email, including your unique links that will allow you access to the meeting and will also permit you to submit questions.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY

MATERIALS FOR THE STOCKHOLDER MEETING

TO BE HELD ON JUNE 4, 2024

Our Proxy Statement and Annual Report are also available online at

www.proxydocs.com/ACIW

2024 PROXY STATEMENT

Proxy Statement Table of Contents

2024 PROXY STATEMENT i

2024 PROXY STATEMENT iii

Proxy Statement for the Annual Meeting of Stockholders to be held on June 4, 2024

About ACI

ACI Worldwide is a global leader in mission-critical, real-time payments software. Our proven, secure and scalable software solutions enable leading corporations, fintechs and financial disruptors to process and manage digital payments, power omni-commerce payments, present and process bill payments, and manage fraud and risk. We combine our global footprint with a local presence to drive the real-time digital transformation of payments and commerce.

In this Proxy Statement, the terms “ACI,” the “Company,” “we,” and “our” refer to ACI Worldwide, Inc.

This Proxy Statement contains a report issued by the Audit Committee relating to certain of its activities during 2023 and a report issued by the Compensation and Leadership Development Committee relating to executive compensation during 2023. Stockholders should be aware that under Securities and Exchange Commission rules, these committee reports are not considered “filed” with the Securities and Exchange Commission under the Securities Exchange Act of 1934 and are not incorporated by reference in any past or future filing by ACI Worldwide, Inc. under the Securities Exchange Act of 1934 or the Securities Act of 1933, unless specifically referenced. Additionally, the information contained on aciworldwide.com is not incorporated by reference into this Proxy Statement.

These materials were first made available to stockholders on April 22, 2024.

Date, Time and Place of Meeting

This Proxy Statement is being furnished in connection with the solicitation by and on behalf of the Board of proxies to be used at our 2024 Annual Meeting of Stockholders, and any postponement or adjournment thereof. A copy of our annual report on Form 10-K for the fiscal year ended December 31, 2023 (the “Annual Report”), accompanies this Proxy Statement.

2024 PROXY STATEMENT 1

Questions and Answers about this Proxy Material and Voting

Why am I receiving these materials?

We are making these proxy materials available because the Board of Directors (the “Board of Directors” or the “Board”) of ACI is soliciting your proxy to vote at the 2024 Annual Meeting of Stockholders (the “Annual Meeting”). You are invited to attend the Annual Meeting via audio only webcast to vote on the proposals described in this Proxy Statement so long as you register to attend the Annual Meeting at www.proxydocs.com/ACIW. You will be asked to provide the control number located inside the shaded box on your Notice or proxy card (the “Control Number”) as described in the Notice of Internet Availability of Proxy Materials (the “Internet Availability Notice”) or proxy card. After completion of your registration by the Registration Deadline, further instructions, including a unique link to access the Annual Meeting, will be emailed to you. If you request a printed copy of our proxy materials by mail, your broker or nominee will provide a voting instruction card for you to use.

You do not need to attend the Annual Meeting to vote your shares. Instead, you may follow the instructions below to submit your proxy by telephone or on the Internet, or complete, sign and return the proxy card.

Under the U.S. Securities and Exchange Commission’s (the “SEC”) “notice and access” rules, ACI has elected to use the Internet as its primary means of furnishing proxy materials to our stockholders. Consequently, most stockholders will not receive paper copies of ACI’s proxy materials. ACI intends to commence mailing to all stockholders of record entitled to vote at the Annual Meeting the Internet Availability Notice on or about April 22, 2024 . The Internet Availability Notice will include instructions on how to receive a paper copy of your proxy materials, if you so choose.

ACI’s office is located at 6060 Coventry Drive, Elkhorn, NE 68022; our telephone number is (402) 390-7600.

Why did I receive a notice in the mail regarding the Internet availability of proxy materials instead of a full paper copy of this Proxy Statement and Annual Report to Stockholders?

We are acting under a Securities and Exchange Commission rule that allows companies to furnish their proxy materials over the Internet rather than in paper form. This rule allows a company to send its stockholders a notice regarding Internet availability of proxy materials. Instructions on how to access the proxy materials over the Internet or how to request a paper copy of proxy materials may be found in the Internet Availability Notice.

How can I attend the Annual Meeting?

This year’s Annual Meeting will be accessible through the Internet via a live audio-only webcast. Prior registration to attend the Annual Meeting at www.proxydocs.com/ACIW is required. You are entitled to participate at the Annual Meeting if you were a stockholder as of the close of business on our record date of April 9, 2024 or hold a valid proxy for the meeting. To be admitted to the Annual Meeting’s live audio-only webcast, you must register at www.proxydocs.com/ACIW as described in the Internet Availability Notice or proxy card. As part of the registration process, you must enter the Control Number. After completion of your registration by the Registration Deadline, further instructions, including a unique link to access the Annual Meeting, will be emailed to you.

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Who can vote at the Annual Meeting?

You will be entitled to vote at the Annual Meeting if you owned ACI’s common stock (“Common Stock”), either as a stockholder of record or as a beneficial owner, as of the close of business on April 9, 2024 (the “Record Date”). On the Record Date, there were 106,255,858 shares of Common Stock outstanding. Holders of these outstanding shares are entitled to one vote for each share of Common Stock held by them as of April 9, 2024 at the Annual Meeting. Shares of Common Stock held as treasury stock are not entitled to be voted at the Annual Meeting. Each stockholder is entitled to one vote per share of Common Stock held on all matters to be voted on by stockholders. Unless context requires otherwise, any reference to “shares” in this Proxy Statement refers to all shares of Common Stock entitled to vote at the Annual Meeting.

If your shares are registered directly in your name with our transfer agent, EQ Shareowner Services, the Internet Availability Notice was sent directly to you by ACI. The Internet Availability Notice provides instructions on how to request printed proxy materials and how to access your proxy card, which contains instructions on how to vote via the Internet or by telephone. For stockholders who receive a paper proxy card, instructions for voting via the Internet or by telephone are set forth on the proxy card. If your shares are held in an account at a brokerage firm, bank, trust, or other similar organization, like the vast majority of our stockholders, you are considered the “beneficial owner” of shares held in “street name” and the Internet Availability Notice was forwarded to you by that organization. You will receive instructions from your broker, bank, trustee, or other nominee that must be followed in order for your broker, bank, trustee, or other nominee to vote your shares per your instructions.

What am I voting on?

There are three matters scheduled for a vote:

How do I vote?

For Proposal No. 1, you may either vote “For”, vote “Against” or vote to “Abstain” with respect to each of the nominees for the Board of Directors. You may not vote your proxy “For” the election of any persons other than the eight named nominees. For all other matters to be voted on, you may vote “For” or “Against” or abstain from voting on the applicable proposal.

Stockholder of Record: Shares Registered in Your Name

If you are a stockholder of record, you may vote by proxy using a proxy card, vote by proxy on the Internet or by telephone as set forth in the Internet Availability Notice, or vote at the Annual Meeting. Regardless of whether you plan to attend the Annual Meeting via audio-only webcast, we urge you to vote by proxy to ensure your vote is counted. You may still attend the Annual Meeting and vote if you have already voted by proxy.

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Beneficial Owner: Shares Registered in the Name of a Broker or Bank

See “Who can vote at the Annual Meeting?” for voting instructions if you beneficially own shares held in street name.

How many votes do I have?

On each matter to be voted upon, you have one vote for each share of Common Stock you own as of the close of business on April 9, 2024.

What if I return a proxy card but do not make specific choices?

If you return a signed and dated proxy card without marking any voting selections, your shares will be voted as follows:

If any other matter is properly presented at the meeting, your proxy (one of the individuals named on your proxy card) will vote your shares using his or her best judgment.

Who is paying for this proxy solicitation?

ACI will pay for the entire cost of soliciting proxies, including the preparation, assembly, printing and mailing of the Internet Availability Notice, this Proxy Statement, the proxy and any additional solicitation materials that ACI may provide to stockholders. Copies of the proxy materials and any other solicitation materials will be provided to brokerage firms, banks, fiduciaries and custodians holding shares in their names that are beneficially owned by others so that they may forward the solicitation materials to such beneficial owners. ACI will reimburse such brokerage firms, banks, fiduciaries and other custodians for the reasonable out-of-pocket expenses incurred by them in connection with forwarding the proxy materials and any other solicitation materials.

In addition to ACI mailing these proxy materials, the Internet Availability Notice and the Annual Report (as applicable), ACI’s directors and employees may also solicit proxies in person, by telephone or by other means of communication. Directors and employees will not be paid any additional compensation for soliciting proxies. Mediant Communications LLC will monitor voting and deliver executed proxies to our voting tabulator.

What does it mean if I receive more than one set of proxy materials?

If you receive more than one set of proxy materials (including multiple copies of this Proxy Statement and multiple proxy cards or multiple Internet Availability Notices), your shares are registered in more than one name or are registered in different accounts. Please complete, date, sign and return each proxy card to ensure that all of your shares are voted.

Can I change my vote after submitting my proxy?

Yes. You can revoke your proxy at any time before the final vote at the Annual Meeting.

If you are a stockholder of record, you may revoke your proxy in any one of the following ways:

If you are a beneficial owner of our shares, you will need to contact your bank, brokerage firm, trustee, or other nominee to revoke any prior voting instructions.

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How are votes counted?

Votes will be counted by the inspector of elections appointed for the meeting as follows:

Proposal No. 1. The inspector of elections will count “For” votes, “Against” votes and votes to “Abstain.” Abstentions and broker non-votes will not affect the outcome of Proposal No. 1.

Proposal No. 2. The inspector of elections will count “For” and “Against” votes. Abstentions will have the effect of a vote against the proposal. Brokers have discretionary voting authority to vote on Proposal No. 2 in the absence of voting instructions from their customers. As a result, there should be no broker non-votes with respect to this proposal, but if there are any such broker non-votes, they will not affect the outcome of Proposal No. 2.

Proposal No. 3. The inspector of elections will count “For” and “Against” votes. Broker non-votes will not affect the outcome of Proposal No. 3. Abstentions will have the effect of a vote against the proposal.

See “How many votes are needed to approve each proposal?” for further details regarding the votes needed to approve each proposal.

What is a “broker non-vote”?

If your shares are held by your broker, bank or other similar organization as your nominee (that is, in “street name”), you will need to follow the voting instructions provided by that organization on how to vote your shares. If you do not provide voting instructions, your shares may constitute “broker non-votes.” Generally, broker non-votes occur on a matter when a broker, bank, or other organization is not permitted to vote on that matter, including the election of directors or executive compensation matters, without instructions from the beneficial owner and instructions are not given. We encourage you to provide instructions to your broker or other nominee regarding voting your shares. On any matter for which your broker or other nominee does not vote on your behalf, the shares will be treated as “broker non-votes.”

Broker non-votes will be counted for purposes of determining the presence or absence of a quorum for the transaction of business at the Annual Meeting, but broker non-votes will not be counted for purposes of determining the number of shares present or represented by proxy at the Annual Meeting with respect to a particular proposal on which the broker has expressly not voted. See “How are votes counted?” for further details regarding the effect of broker non-votes on the proposals set forth in this Proxy Statement.

How is an abstention counted?

Abstentions will be counted for purposes of determining the presence or absence of a quorum. The effect of an abstention on the outcome of the voting on a particular proposal depends on the vote required to approve that proposal, as described in the “How many votes are needed to approve each proposal?” section below.

How many votes are needed to approve each proposal?

Proposal No. 1. We have a majority voting standard for uncontested elections of directors, including the election of directors in the Annual Meeting. Under our Bylaws, the number of shares voted “For” a director’s election must exceed 50% of the number of votes cast with respect to that director’s election. A director standing for re-election who fails to receive the required number of votes is expected to tender his or her resignation, which resignation will be accepted in the Board’s exclusive discretion. The Board will only nominate for election or re-election candidates who agree to tender an irrevocable resignation upon failure to receive the required vote.

In contested elections – where the number of nominees exceeds the number of directors to be elected – each director will be elected by a plurality of the votes cast.

Proposal No. 2. Ratification of the appointment of Deloitte & Touche LLP as ACI’s independent registered public accounting firm for the fiscal year ending December 31, 2024 requires the affirmative “For” vote of a majority in voting power of the votes cast by the holders of all shares present, or represented by proxy, and voting affirmatively or negatively on such matter.

2024 PROXY STATEMENT 5

Proposal No. 3. Approval, on an advisory basis, of the compensation of our named executive officers as disclosed in this Proxy Statement requires the affirmative “For” vote of a majority in voting power of the votes cast by the holders of all shares present, or represented by proxy, and voting affirmatively or negatively on such matter.

See “How are votes counted?” for further details regarding the effect of abstentions and broker-non votes on the proposals set forth in this Proxy Statement.

What are the Board’s voting recommendations?

What is the quorum requirement?

A quorum of stockholders is necessary to hold a valid meeting. A quorum will be present if a majority of all outstanding shares is represented by stockholders at the Annual Meeting, by means of remote communication or represented by proxy. On the Record Date, there were 106,255,858 shares of Common Stock issued, outstanding and entitled to vote, which number excludes 34,269,197 shares of Common Stock held as treasury stock by ACI. Thus, 53,127,930 shares must be represented by stockholders present at the Annual Meeting or represented by proxy to have a quorum. Your shares will be counted towards the quorum if you submit a valid proxy or vote at the Annual Meeting. In addition, under the General Corporation Law of the State of Delaware, abstentions and broker non-votes will be counted as present for the purpose of determining the presence of a quorum.

How can I find out the results of the voting at the Annual Meeting?

Preliminary voting results will be announced at the Annual Meeting. Final voting results will be published in a Current Report on Form 8-K within four business days following the Annual Meeting. In the event we are unable to obtain the final voting results within four business days, we will file the preliminary voting results in a Current Report on Form 8-K within four business days following the Annual Meeting and will file an amended Form 8-K with the final voting results within four business days after the final voting results are known.

How can stockholders submit a proposal for inclusion in our Proxy Statement for the 2025 annual meeting of stockholders?

To be included in our proxy statement for the 2025 annual meeting of stockholders, stockholder proposals must comply with the requirements of Rule 14a-8 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Except as provided below, stockholder proposals must be received by our Secretary at our principal executive offices no later than December 23, 2024. The Corporate Governance Committee will review proposals submitted by stockholders for inclusion at our next annual meeting of stockholders and will make recommendations to our Board on an appropriate response to such proposals.

How can stockholders submit proposals to be raised at the 2025 annual meeting of stockholders that will not be included in our proxy statement for the 2025 annual meeting of stockholders?

To be raised at the 2025 annual meeting of stockholders, stockholder proposals must comply with our Bylaws. To be timely, a stockholder’s notice of a proposal must be delivered to or mailed and received at our principal executive offices not earlier than February 4, 2025 and not later than March 6, 2025. Under our proxy access bylaw, if a stockholder (or a group of up to 20 stockholders) who has owned at least 3% of our shares for at least three years and has complied with the other requirements set forth in our Bylaws wants us to include director nominees (up to the greater of two nominees or 20% of the Board) in our 2025 proxy statement and form of proxy for election at our 2025 Annual Meeting of Stockholders, the nominations must be

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received by ACI’s Secretary at ACI’s office located at 6060 Coventry Drive, Elkhorn, NE 68022 not earlier than November 23, 2024 and not later than December 23, 2024. If a stockholder wishes only to recommend a candidate for consideration by the Nominating and Corporate Governance Committee as a potential nominee for director, see the procedures discussed in “Stockholder Communications with our Board.” Any stockholder considering a proxy access nomination should carefully review our Bylaws, which are available on our website at aciworldwide.com.

In addition to satisfying the requirements under our Bylaws, stockholders who intend to solicit proxies in support of director nominees other than our nominees must provide notice that sets forth the information required by Rule 14a-19 under the Exchange Act to comply with the universal proxy rules, which notice must be postmarked or transmitted electronically to us at our principal executive offices no later than April 5, 2025. However, if the date of the 2025 Annual Meeting is changed by more than 30 calendar days from such anniversary date, then notice must be provided by the later of 60 calendar days prior to the date of the 2025 Annual Meeting or the 10th calendar day following the day on which public announcement of the date of the 2025 Annual Meeting is first made.

What if the date of the 2025 annual meeting of stockholders changes by more than 30 days from the anniversary of this year’s Annual Meeting?

Under Rule 14a-8 of the Exchange Act, if the date of the 2025 annual meeting of stockholders changes by more than 30 days from the anniversary of this year’s Annual Meeting, to be included in our proxy statement for such meeting, stockholder proposals must be received by us within a reasonable time before our solicitation is made. Under our Bylaws, if the date of the annual meeting is advanced more than 30 calendar days prior to or delayed by more than 30 calendar days after the anniversary of the preceding year’s annual meeting, notice by the stockholder to be timely must be so delivered not later than the close of business on the later of (A) the 90th calendar day prior to such annual meeting and (B) the 10th calendar day following the day on which public disclosure of the date of such meeting is first made.

Does a stockholder proposal require specific information?

To be included in our proxy statement, stockholder proposals must comply with the requirements of Rule 14a-8 under the Exchange Act. With respect to a stockholder’s nomination of a candidate for our Board, the stockholder notice to our Secretary must contain certain information as set forth in our Bylaws about both the nominee and the stockholder making the nomination. With respect to any other business that the stockholder proposes, the stockholder notice must contain a brief description of such business and the reasons for conducting such business at the meeting, as well as certain other information as set forth in our Bylaws. If you wish to bring a stockholder proposal or nominate a candidate for director, you are advised to review Rule 14a-8 under the Exchange Act and our Bylaws, as applicable, which contain additional requirements about advance notice of stockholder proposals and director nominations. Pursuant to Rule 14a-4(c) under the Exchange Act, if ACI does not receive advance notice of a stockholder proposal to be brought before its next annual meeting of stockholders in accordance with the requirements of its Bylaws, the proxies solicited by ACI may confer discretionary voting authority to vote proxies on the stockholder proposal without any discussion of the matter in the proxy statement.

2024 PROXY STATEMENT 7

Corporate Governance

Our corporate governance practices and the diverse skills and attributes that our directors bring to ACI support our business as a global payments software company. All our director nominees have served in leadership roles and, except for our CEO, all nominees are independent. Through proactive evaluation and assessment, our Board can adapt and ensure that the right skills and experience are represented on our Board.

Our corporate governance structure is designed to serve the best interests of our stockholders.

ACI’s key governance documents, including our Corporate Governance Guidelines, Code of Business Conduct and Ethics and charters for each of our Board committees, are available on our website at aciworldwide.com.

Board of Directors and Committees

Our Board has three standing committees: the Audit Committee, the Compensation and Leadership Development Committee, and the Nominating and Corporate Governance Committee. The following table provides membership information for each of the standing Board committees as of April 22, 2024:

Name		Audit		Compensation  and Leadership Development		Nominating and Corporate  Governance		Independent		Tenure(1)		# of Other Public Company Boards(4)
Adalio T. Sanchez (Chairman)								Y		9		2
Juan A. Benitez(2)								Y		0		0
Janet O. Estep								Y		8		1
James C. Hale III(3)								Y		8		2
Mary P. Harman								Y		3		0
Katrinka B. McCallum(2)								Y		0		2
Charles E. Peters, Jr								Y		9		0
Thomas W. Warsop III								N		9		0
Samir M. Zabaneh								Y		3		1

Chair     Member

⁽¹⁾ Full years of service as of the annual meeting date

⁽²⁾ Mr. Benitez and Ms. McCallum were elected to the Board in February 2024, and their Committee assignments were not established as of the date of this Proxy Statement.

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⁽³⁾ Mr. Hale will serve the remainder of his term, which will end at the Annual Meeting.

⁽⁴⁾ For purposes herein, a public company is a company that has a class of securities registered pursuant to Section 12 of the Securities Exchange Act of 1934 or is subject to the requirements of Section 15(d) of the Securities Exchange Act of 1934.

Director Independence

Our Board follows the NASDAQ listing standards requirements on director independence. Our Board reviews at least annually the independence of each director. During these reviews, the Board considers transactions and relationships between each director (and his or her immediate family and affiliates) and ACI and its management to determine whether any transactions or relationships are inconsistent with a determination that the director is independent. This review is based primarily on responses of the directors to questions in a directors’ and officers’ questionnaire regarding employment, business, familial, compensation and other relationships with us and our management.

The Board has determined that each of our directors is independent, except Thomas W. Warsop, III, our President and CEO.

As required by NASDAQ, our independent directors meet in regularly scheduled executive sessions at which only independent directors are present.

Board Committees

The Audit Committee operates under a formal charter, which is available on our website at https://investor.aciworldwide.com/. Our Audit Committee assists our Board in its general oversight of financial reporting, internal controls and audit functions and is directly responsible for the appointment, retention, compensation and oversight of the work of our independent registered public accounting firm. Our Audit Committee also provides oversight of ACI’s enterprise risk management, business continuity and information security programs. The Audit Committee oversees ACI’s major financial risk exposures, including cybersecurity risks and ESG risks, and monitors the steps taken by management to control such exposures.

The Audit Committee has the power to investigate any matter brought to its attention within the scope of its duties and the authority to retain counsel and advisors at our expense to fulfill its responsibilities and duties.

Our Audit Committee is comprised of Ms. Estep, Mr. Hale, Mr. Peters, and Mr. Zabaneh. Mr. Hale will cease to serve as a member of the Audit Committee at the end of his term as a director, which will end at the Annual Meeting. Mr. Peters is the Chair of the Committee. Each member other than Ms. Estep is an “audit committee financial expert” as defined under the rules of the SEC implementing Section 407 of the Sarbanes Oxley Act of 2002. The Audit Committee met eight times during the year ended December 31, 2023.

Our Board has considered the independence and other characteristics of each member of our Audit Committee and has concluded that the composition of our Audit Committee meets the requirements for independence under the current requirements of SEC rules and regulations. Audit Committee members must satisfy additional independence criteria set forth under Rule 10A-3 under the Exchange Act. In order to be considered independent for purposes of the Rule 10A-3, an Audit Committee member may not, other than in his or her capacity as a member of the audit committee, accept consulting, advisory or other fees from us or be an affiliated person. Each of the members of our Audit Committee qualifies as an independent director pursuant to Rule 10A-3.

See the “Report of the Audit Committee” below.

The Compensation and Leadership Development Committee (the “Compensation Committee”) operates under a formal charter, which is available on our website at https://investor.aciworldwide.com/. Our Compensation Committee reviews, determines and recommends salaries, performance-based incentives and other matters relating to executive compensation; reviews, evaluates and approves our equity-linked plans, including reviewing and granting equity awards to our executive officers; recommends to the independent directors CEO compensation based on the CEO’s performance; reviews and evaluates the performance of, and compensation for, executive officers other than our CEO; oversees and evaluates the integration of any of the Company’s ESG goals into the Company’s executive compensation programs; and provides general oversight of leadership development processes and strategies for executive and senior officers.

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The Compensation Committee also has the power to investigate any matter brought to its attention within the scope of its duties and the authority to retain counsel and advisors at our expense to fulfill its responsibilities and duties.

Our Compensation Committee is comprised of Mr. Hale, Ms. Harman, and Mr. Zabaneh. Mr. Zabaneh is the Chair of the Committee. Mr. Hale will cease to serve as a member of the Compensation Committee at the end of his term as a director, which will end at the Annual Meeting. Each of the Compensation Committee members meets the independence requirements set forth in the rules of NASDAQ, and the “non-employee director” standard within the meaning of Rule 16b-3(b)(3) promulgated under the Exchange Act. The Compensation Committee met six times during the year ended December 31, 2023.

The Compensation Committee may delegate authority to a subcommittee or an individual Compensation Committee member as the Compensation Committee deems necessary, provided that the decisions of such members will be presented to the full Compensation Committee at its next scheduled meeting. For information regarding the role of executive officers and the Compensation Committee’s compensation consultant in determining or recommending the amount or form of executive compensation, see the Compensation Discussion and Analysis.

The Nominating and Corporate Governance Committee (the “Corporate Governance Committee”) operates under a formal charter, which is available on our website at https://investor.aciworldwide.com/.

The Corporate Governance Committee assists our Board in ensuring that we are governed in a manner consistent with the interests of our stockholders, including the integration of corporate responsibility and ESG principles into our business strategy and decision making. The Corporate Governance Committee conducts the Board evaluations and assessments, including assessments of stockholder nominees to the Board, and the identification and recommendation of director nominees. The Corporate Governance Committee also assists the Board in its evaluation of the Board and its committees, as well as the succession planning for our CEO and other executive officers.

The Corporate Governance Committee has the power to investigate any matter brought to its attention within the scope of its duties and the authority to retain counsel and advisors at our expense to fulfill its responsibilities and duties.

The Corporate Governance Committee is comprised of Ms. Estep, Ms. Harman, and Mr. Peters. Ms. Harman is the Chair of the Committee. Each of the committee members meets the independence requirements set forth in the rules of NASDAQ. The Corporate Governance Committee met five times during the year ended December 31, 2023.

Meeting Attendance

Our Board and committees held the following meetings during 2023:

Each director attended at least 75% of Board and applicable committee meetings in 2023.

Director nominees are expected to attend our annual meetings of stockholders. All of the 2023 director nominees attended our 2023 annual meeting.

Board Leadership Structure

Mr. Sanchez is the Chairman of the Board. Mr. Warsop III, our CEO, is the only member of the Board who is not an independent director. We believe that this leadership structure enhances the accountability of our CEO to the Board and strengthens the Board’s independence from management.

Board Evaluation and Nomination Process

The Board believes that a continuous evaluation process allows it to assess its effectiveness and proactively identify gaps in desired skills and attributes represented on the Board.

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The Corporate Governance Committee oversees an annual review process. An evaluation is completed with respect to each director, each committee and the Board as a whole. Additionally, interviews are held with each director and an independent board assessment firm.

Corporate Responsibility and Sustainability

ACI believes businesses have an increasingly important mandate to operate responsibly, and we aim to operate in a way that is socially, environmentally and financially sustainable. We find ways to improve the lives of our employees and positively impact the communities in which we live and work.

ESG Governance

ACI’s ESG governance structure includes four groups. The Board of Directors, through the Nominating and Corporate Governance Committee, has oversight responsibility to implement and review the Company’s ESG programs and practices. Various committees of the Board also review relevant aspects of the Company’s ESG programs and practices. The Board reviews progress made against our ESG priorities and provides the final review and approval of our annual sustainability report. Executive Leadership Team members provide guidance and manage the execution of ESG priorities, especially those aligned to their business units. Key Senior Leadership Team members are dedicated to advancing ESG priorities. They also provide day-to-day initiative management. Working groups assembled from employee volunteers help advance the implementation of specific initiatives.

Sustainable Solutions

We recognize the essential role digital payment systems play in our modern economy and how they can open life’s possibilities to everyone, including people historically disadvantaged by location, education, disability, race, gender, ethnicity, wealth or circumstance. We are proud that our core products and services can help ensure inclusive and equitable access to the digital economy and can eliminate the need for paper-based bills and payments, saving trees the world needs to provide oxygen, improve air quality, conserve water, support wildlife and mitigate climate change.

Corporate Social Responsibility Initiatives

Some of our key environmental efforts include reducing our energy use and waste production through the implementation of LED lighting, managed HVAC systems, electronic signature and agreement software and more efficient data center technology. We have also adopted a single-stream recycling program in the U.S. and have programs in place globally to reduce paper and plastic consumption. We also work with credible vendors for responsible processing and recycling of electronic devices. In 2021, we completed an office optimization initiative that reduced our global office footprint and further lessened our energy use and waste production. In 2022, we continued to invest in energy improvements while also advancing our sustainability reporting. We published an enhanced Sustainability Report to provide all stakeholders with a more detailed narrative of our environmental, social and governance efforts. The report includes our first energy usage data and detailed appendices aligned to Sustainability Standards Board (SASB) and Global Reporting Initiative (GRI) reporting standards. In 2023, we inventoried our Scope 1 and Scope 2 greenhouse gas (GHG) emissions. The data shows that nearly all of our emissions come from purchased electricity. Our emissions analysis is included in our 2023 Sustainability Report.

Financial inclusion, gender parity in payments and STEM education are our social areas of focus. We have philanthropic relationships with Girls Who Code and Code.org to introduce more children from underrepresented groups to computer science. We also donate to Kiva, a non-profit that facilitates small loans to low-income entrepreneurs and students globally. We are a sponsor of Women in Payments and Paytech, organizations dedicated to giving women in the industry more opportunities to excel. In 2022, we launched RISE (Represent, Include, Strengthen, Development), a multi-faceted leadership development program that aims to inspire and empower high-potential ACI leaders from underrepresented groups to actively participate in business decision making, accelerating their professional advancement and ACI’s growth journey. In addition, our thousands of team members located in 49 countries around the world have a powerful impact in their own communities when they use their eight hours of paid volunteer time a month to give back to a variety of non-governmental organizations.

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Board Diversity

The Board is committed to diversity and inclusiveness, including in respect of the composition of the Board itself. Three of the eight, or 37.5%, of the director nominees self-identify as gender diverse. Three of the director nominees self-identify as other than white

The following Board Diversity Matrix sets forth diversity statistics regarding each of the director nominees, which comprise our current directors other than Mr. Hale, who will serve the remainder of his term, which will end with the Annual Meeting.

Board’s Role in Risk Oversight

Risk is inherent with every business and we face a number of risks, including strategic, financial, operational, cybersecurity, privacy, legal/compliance, governance and reputational risks. Our management is responsible for the day-to-day management of the risks that we face. Our Board as a whole has responsibility for the oversight of enterprise risk management. Our Board provides broad oversight of ACI’s risk management programs. In this oversight role, our Board considers the implementation and effectiveness of the Company’s risk management processes. The involvement of our full Board in the risk oversight process allows our Board to assess management’s tolerance for risk and also to determine what constitutes an appropriate level of risk for ACI.

While our Board provides broad oversight, various committees of the Board oversee risk management in their respective areas and regularly report on their activities to the entire Board.

The Audit Committee focuses on assessing and mitigating financial risk, including internal controls, and receives an annual risk assessment report from ACI’s internal auditors. As part of its annual audit, ACI’s independent registered accounting firm, Deloitte & Touche LLP, also provides the Audit Committee with a risk assessment identifying risks of material misstatements and related controls. The Audit Committee reviews these and other reports on risks facing the Company at its meetings throughout the year. The Audit Committee also reviews with management ACI’s enterprise risk management, business continuity and information security programs.

The Compensation Committee reviews and oversees the management of potential material risks related to ACI’s compensation policies and practices. Compensia, the independent compensation consultant retained by the Compensation Committee, provides an annual assessment of such risks. The Compensation Committee reviews this annual assessment and evaluates such risks as it considers compensation and benefits matters throughout the year.

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The oversight roles of the Board and the committees are supported by management reporting processes that are designed to provide the Board and the committees with visibility into the identification, assessment and management of critical risks.

Code of Business Conduct and Ethics

Under our Code of Business Conduct and Ethics our directors and employees, including our executive officers, must promptly report any transaction, relationship, or circumstance that creates or may create a conflict of interest. Any conflict of interest for our non-director and non-executive officer employees is prohibited unless a waiver is obtained from our General Counsel. Conflicts of interest involving our directors and executive officers are prohibited unless waived by our Board. Any waiver of a conflict of interest involving one of our directors or executive officers will be promptly disclosed in accordance with applicable law and NASDAQ listing requirements. The full text of our Code of Business Conduct and Ethics is, and any amendment to or waiver from a provision of our Code of Business Conduct and Ethics will be, posted on our website at https://investor.aciworldwide.com/corporate-govemance.

We also have a Code of Ethics for the CEO and Senior Financial Officers that requires that our CEO, CFO, Chief Accounting Officer, Controller and persons performing similar functions avoid actual and apparent conflicts of interest in personal and professional relationships and that they disclose to the Audit Committee any material transaction or relationship that reasonably could be expected to give rise to a conflict. The full text of our Code of Ethics for the CEO and Senior Financial Officers is, and any amendment to or waiver from a provision of our Code of Ethics for the CEO and Senior Financial Officers will be, posted on our website at https://investor.aciworldwide.com/corporate-governance.

Compensation Risk Analysis

The Compensation Committee has concluded that ACI’s compensation policies and practices do not create risks that are reasonably likely to have a material adverse effect on ACI. The Compensation Committee believes that the following features of its compensation program help ensure that management performance is focused on long-term stockholder value creation without encouraging unnecessary or excessive risk-taking:

2024 PROXY STATEMENT 13

Proposal 1 — Election of Directors

Our Board has nominated for election as directors Adalio T. Sanchez, Juan A. Benitez, Janet O. Estep, Mary P. Harman, Katrinka B. McCallum, Charles E. Peters, Jr, Thomas W. Warsop III, and Samir M. Zabaneh, each to serve until the 2025 Annual Meeting of Stockholders and thereafter until his or her respective successor is duly elected and qualified. We expect that each of the nominees will be available for election, but if any of them is unwilling or unable to serve as a candidate at the time the election occurs, it is intended that each share represented by proxy at the Annual Meeting will be voted for the election of another nominee to be designated by the Board to fill any such vacancy.

General

Our Corporate Governance Committee considers, and our Board selects, nominees with a view to establishing a Board that is comprised of members who:

• Possess the skills and attributes described below   • Are independent and free of any conflicts of interest   • Are willing and able to devote sufficient time to the affairs of ACI   • Have the capacity and desire to represent the balanced, best interest of our stockholders   • Bring diverse perspectives to our Board

We believe that each director nominee brings these qualifications to our Board, providing a diverse complement of specific business skills and experience aligned with our business needs.

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Specific Skills and Attributes to be Represented on the Board

To effectively serve ACI’s business and long-term strategy, the Board believes it is important that the following key skills and attributes be represented on the Board as a whole:

2024 PROXY STATEMENT 15

Director Nominees

The following provides biographical information regarding our director nominees and describes the key skills, experience and expertise that each director nominee brings to our Board.

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2024 PROXY STATEMENT 17

2024 PROXY STATEMENT 19

2024 PROXY STATEMENT 21

Director Compensation

Compensation for our independent directors consists of a cash retainer fee based on Board and committee service and an annual equity award based on Board service. Our Board believes that providing a meaningful portion of compensation in the form of equity creates a direct linkage with company performance and stockholder interests.

The Corporate Governance Committee annually reviews the total compensation of our independent directors and each element of our independent director compensation program. Based on its review, the Corporate Governance Committee makes a recommendation to the Board. The Board then determines the form and amount of independent director compensation after reviewing the recommendation.

As part of its annual review, the Corporate Governance Committee asks its independent compensation consulting firm, Compensia, Inc., to provide an assessment of the competitiveness of the Board’s compensation program. In order to assess the competitiveness of the Board compensation program, Compensia used the market data of our peer group, which is the group of companies used for our executive compensation review (see “Compensation Discussion and Analysis—Peer Group” below). The assessment reviews all elements of director compensation (e.g., annual retainers, equity compensation, committee member compensation, committee chair additional compensation and non-executive chairman compensation). In addition, the assessment evaluates the director compensation program design to provide the Corporate Governance Committee an understanding of how the program design compares to both best and market practices.

Our 2020 Equity and Incentive Compensation Plan, as amended (“2020 Plan”), provides a $750,000 per year limit on non-employee director compensation.

Retainer Fees

Each independent director receives a $68,000 base annual retainer fee. The Board chair receives an additional $100,000 annual premium. The Chair of the Audit Committee receives an additional $30,000, the Chair of the Compensation Committee receives an additional $20,000, and the Chair of the Corporate Governance Committee receives an additional $15,000 annual premium. Annual retainer fees are paid on a quarterly basis.

Equity-Based Compensation

Our independent directors are granted an annual equity award with a target grant date fair value of $250,000. Such grants are made at the discretion of our Board based on the recommendations of the Corporate Governance Committee. Director equity awards generally vest on the earlier to occur of (i) the date that is one year following the date of grant, and (ii) the day immediately prior to the date of the next annual meeting of our stockholders occurring following the date of grant. The independent directors’ equity awards provide for accelerated vesting upon the director’s death or disability (as such terms are defined in the applicable award agreement). For non-employee directors who join the Board prior to the annual meeting of shareholders, our practice is to grant such directors a pro-rated equity award.

On June 1, 2023, our independent directors at the time were each granted 10,994 restricted stock units (“RSUs”). Ms. McCallum and Mr. Benitez were not members of the Board on the date of grant, and each received a pro-rated equity award for their grant upon the commencement of their service. Mr. Lamouche was not eligible for a 2023 RSU award due to his resignation on June 1, 2023.

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2023 Director Compensation

The table below summarizes the compensation we paid to our independent directors for the fiscal year ended December 31, 2023.

The following table sets forth each independent director’s aggregate number of stock awards (unvested RSUs) outstanding as of December 31, 2023:

Director Stock Ownership Guidelines

The Board has stock ownership guidelines designed to further link the interests of our Board with those of our stockholders. These guidelines provide that each of our independent directors should have equity positions in ACI with a value equal to five times his or her annual retainer amount (base retainer only). Direct and indirect stock ownership, including the vested in-the-money portion of any stock options held by the independent director, are included in determining each director’s equity position. Each independent director has five years to achieve the target ownership level. A director who fails to meet the ownership guidelines within the five-year period will not be eligible for new equity awards until the director achieves his or her prescribed ownership level. All independent directors are in compliance with our stock ownership guidelines.

2024 PROXY STATEMENT 23

Report of the Audit Committee

At all times during 2023, each member of the Audit Committee was “independent” as defined in the NASDAQ listing standards. Our Board determined that each member met the NASDAQ regulatory requirements for financial literacy, and all members, other than Ms. Estep, are “audit committee financial experts” as defined under SEC rules.

The Audit Committee operates pursuant to a charter, a copy of which is available on our website at aciworldwide.com.

The Audit Committee, on behalf of our Board, oversees ACI’s financial reporting process as more fully described in its charter. Management is responsible for the preparation, presentation and integrity of ACI’s consolidated financial statements, accounting and financial reporting principles, internal controls over financial reporting and compliance with laws and regulations and ethical business standards. Management is responsible for objectively reviewing and evaluating the adequacy, effectiveness and quality of ACI’s system of internal controls. Audit Committee members are not professional accountants or auditors, and their functions are not intended to duplicate or to certify the activities of management or the independent registered public accounting firm.

ACI’s independent registered public accounting firm, Deloitte & Touche LLP (“Deloitte”), is responsible for performing independent audits of ACI’s consolidated financial statements and the effectiveness of ACI’s internal controls over financial reporting in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”) and to issue reports thereon. In fulfilling its oversight responsibilities, the Audit Committee (i) reviewed and discussed the audited consolidated financial statements and the footnotes thereto in ACI’s annual report on Form 10-K for 2023 with management and Deloitte, and (ii) discussed with management and Deloitte the quality, not just the acceptability, of the accounting principles, the reasonableness of significant judgments and the clarity of the disclosures in the financial statements. The Audit Committee discussed with Deloitte the matters required to be discussed by PCAOB Auditing Standard No. 1301 “Communication with Audit Committees”, Rule 2-07 “Communication with Audit Committees” of Regulation S-X, and other PCAOB Rules and Standards. The Audit Committee discussed with ACI’s internal auditors and Deloitte, with and without management present, their evaluations of ACI’s internal accounting controls and reviewed with management the basis for management’s assessment of the effectiveness of ACI’s internal controls over financial reporting. The Audit Committee has also discussed with Deloitte the matters required to be discussed by the Statement on Auditing Standards No. 61, as amended (AICPA, Professional Standards, Vol. 1 AU Section 380), as adopted by the Public Company Accounting and Oversight Board in Rule 3200T.

Deloitte is responsible for expressing opinions on (i) the conformity of ACI’s audited consolidated financial statements, in all material respects, to accounting principles generally accepted in the U.S., and (ii) the effectiveness of ACI’s internal controls over financial reporting. Deloitte has full and free access to the Audit Committee. Deloitte has expressed the opinion that ACI’s audited consolidated financial statements conform, in all material respects, to accounting principles generally accepted in the U.S. The Audit Committee reviewed and discussed with Deloitte its judgments as to the quality, not just the acceptability, of ACI’s accounting principles and such other matters as are required to be discussed by the standards of the PCAOB.

The Audit Committee discussed with Deloitte its independence from management and ACI received from Deloitte the written disclosures and the letter required by applicable requirements of the PCAOB, including as required by PCAOB Ethics and Independence Rule 3526 “Communication with Audit Committees Concerning Independence,” regarding Deloitte’s communications with the Audit Committee concerning independence, and has discussed with Deloitte and management Deloitte’s independence. Upon completing these activities, the Audit Committee concluded that Deloitte is independent from the Company and its management.

In reliance on the reviews and discussions referred to above, the Audit Committee recommended to our Board that the audited consolidated financial statements be included in ACI’s annual report on Form 10-K for 2023 and filed with the Securities and Exchange Commission.

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Proposal 2 — Ratification of Appointment of ACI’s Independent Registered Public Accounting Firm

The Audit Committee has selected and appointed, and our Board has approved, the Audit Committee’s selection and appointment of, Deloitte & Touche LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024. Neither our Bylaws nor other governing documents or law require stockholder ratification of the appointment of Deloitte & Touche LLP as our independent registered public accounting firm. However, the Board is submitting the appointment of Deloitte & Touche LLP to the stockholders for ratification as a matter of good corporate practice. If the stockholders do not ratify the selection, the Audit Committee will consider whether it is appropriate to select another independent registered public accounting firm for the next fiscal year. Even if the selection is ratified by our stockholders, the Audit Committee may, in its discretion, change the appointment at any time during the year if it determines that such a change would be in the best interests of stockholders.

Representatives of Deloitte & Touche LLP are expected to be present at the Annual Meeting to make a statement should they so desire and to respond to appropriate questions.

Independent Registered Public Accounting Firm Fees

The following table sets forth the aggregate fees paid or payable for the indicated services performed by Deloitte during 2023 and 2022 in its capacity as our independent registered public accounting firm during such years.

Audit Fees. This category represents the aggregate fees paid or payable to Deloitte & Touche LLP for professional services rendered for (i) the audit of our annual financial statements and quarterly reviews of ACI’s annual consolidated financial statements for 2023 and 2022, (ii) the audit of the effectiveness of ACI’s internal controls over financial reporting as of December 31, 2023 and December 31, 2022 in accordance with the standards of the PCAOB and (iii) statutory audits of certain subsidiaries.

Audit-Related Fees. This category represents the aggregate fees billed by Deloitte & Touche LLP for professional services rendered for assurance and related services that were reasonably related to the performance of the audit or review of ACI’s financial statements that are not reported under “Audit Fees” for 2023 or 2022.

Tax Fees. This category represents the aggregate fees billed by Deloitte & Touche LLP for tax-related services rendered to ACI for 2023 and 2022. Tax fees billed by Deloitte & Touche LLP in 2023 and 2022 consisted of fees for professional services related primarily to tax compliance, planning, advice, and consulting services.

All Other Fees. There were no other fees billed by Deloitte & Touche LLP for services rendered to ACI during 2023 or 2022, other than the services described above under “Audit Fees,” “Audit-Related Fees” and “Tax Fees.”

2024 PROXY STATEMENT 25

The Audit Committee has considered whether the provision of the services by Deloitte & Touche LLP as described above in “Tax Fees” is compatible with maintaining the independent registered public accounting firm’s independence.

Pre-Approval of Audit and Non-Audit Services

We have policies for pre-approval of all audit and non-audit services to be provided to us by our independent registered public accounting firm and its member firms. Under these policies, all audit and non-audit services to be performed by our independent registered public accounting firm must be approved by the Audit Committee in advance. A proposal for audit and non-audit services must include a description and purpose of the services, estimated fees and other terms of the services. To the extent a proposal relates to non-audit services, a determination that such services qualify as permitted non-audit services and an explanation as to why the provision of such services would not impair the independence of our independent registered public accounting firm are also required. Any engagement letter relating to a proposal must be presented to the Audit Committee for review and approval, and the Chair of the Audit Committee may sign, or authorize an officer to sign, such engagement letter.

All services provided by Deloitte & Touche LLP in 2023 and 2022 were pre-approved by the Audit Committee.

Vote Required

The affirmative vote of a majority of the shares represented at the Annual Meeting and actually voting on this proposal is required for the approval of this proposal.

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Proposal 3 — Advisory Vote to Approve Named Executive Officer Compensation

As required pursuant to Section 14A of the Exchange Act, stockholders are asked to cast an advisory vote on the compensation of our Named Executive Officers as disclosed in this Proxy Statement pursuant to the compensation disclosure rules of the SEC, including the Compensation Discussion and Analysis, the accompanying compensation tables and related narrative disclosures contained in this Proxy Statement. This advisory vote is commonly known as a “say-on-pay” vote.

As described in the Compensation Discussion and Analysis, our executive compensation programs are performance-based programs with a significant portion of each Named Executive Officer’s overall compensation opportunity linked to our annual and long-term financial performance and our long-term relative total shareholder return. The Compensation Committee sets challenging thresholds and target performance levels for each of the metrics in our incentive compensation plans to help ensure that the amounts earned are based upon outstanding performance as measured against pre-established financial, operational and strategic objectives.

We value the feedback from our stockholders regarding our executive compensation programs. As part of our ongoing shareholder dialogue, we regularly seek feedback on these programs, as well as other important issues. Over the last year we proactively reached out to stockholders representing more than two-thirds of our outstanding shares. For the stockholders that were interested in engaging with us, the feedback from our stockholders has been generally positive. The feedback from our stockholders, and our resulting actions, are described in the Compensation Discussion and Analysis.

We urge our stockholders to read the Compensation Discussion and Analysis, the accompanying compensation tables and other related tables and narrative disclosures, which describe in more detail how our executive compensation policies and procedures operate and are designed to achieve our compensation objectives.

Stockholders are being asked to approve the following resolution at the Annual Meeting:

Advisory Vote

As this is an advisory vote, the outcome of the vote is not binding on ACI or the Board. However, we value the opinions expressed by our stockholders and the Compensation Committee will consider the outcome of the vote when making future executive compensation decisions. Currently, advisory say-on-pay votes are scheduled to be held once every year. It is anticipated that our next say-on-pay vote will occur at our 2025 Annual Meeting of Stockholders.

Vote Required

The affirmative vote of a majority of the shares represented at the Annual Meeting and actually voting on this proposal is required for the approval of this proposal.

2024 PROXY STATEMENT 27

Information Regarding Security Ownership

The following table sets forth certain information regarding the beneficial ownership of our common stock as of March 31, 2024 by (i) each of our directors, (ii) each of our Named Executive Officers (as defined in the “Compensation Discussion and Analysis” below), (iii) all of our executive officers and directors as a group, and (iv) each person known by us to beneficially own more than 5% of the outstanding shares of our common stock. The percentages in these tables are based on 106,412,716 outstanding shares of common stock as of March 31, 2024. Beneficial ownership is determined in accordance with the rules of the SEC and generally includes voting and/or investment power with respect to the securities. In computing the number of shares beneficially owned by a person and the percentage ownership of that person, shares underlying options held by that person that will be exercisable within 60 days of March 31, 2024 and shares underlying other equity awards that will vest within 60 days of March 31, 2024 are deemed to be outstanding. Such shares, however, are not deemed to be outstanding for the purpose of computing the percentage ownership of any other person. The following table does not include shares underlying rTSR Performance Share Awards (as defined below) that are subject to vesting to the extent that performance objectives are achieved. No family relationships exist among our directors and executive officers.

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Delinquent Section 16(a) Reports

Section 16(a) of the Exchange Act and the rules of the SEC require our directors, certain officers and beneficial owners of more than 10% of our outstanding common stock to file reports of their ownership and changes in ownership of our common stock with the SEC. ACI employees generally prepare these reports on behalf of our executive officers and directors on the basis of information obtained from them, and we review the forms submitted to us by beneficial owners of more than 10% of our common stock. Based on such information, we believe that all but four reports required by Section 16(a) of the Exchange Act to be filed by our directors, officers and beneficial owners of more than 10% of the common stock during or with respect to 2023 were filed on time. Each of Scott Behrens and Deborah Guerra did not timely file a Form 4 statement of changes in beneficial ownership of securities, but such forms were subsequently filed. Abe Kuruvilla did not timely file a Form 3 initial statement of beneficial ownership of securities and a Form 4 statement of changes in beneficial ownership of securities, but such forms were subsequently filed.

2024 PROXY STATEMENT 29

Equity Compensation Plan Information

The table below summarizes the compensation we paid to our independent directors for the fiscal year ended December 31, 2023.

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Compensation Discussion and Analysis

This Compensation Discussion and Analysis describes the material elements of our executive compensation program during 2023 and provides an overview of our executive compensation philosophy, core principles and objectives. We also discuss how and why the Compensation Committee arrived at the specific compensation decisions for our named executive officers (“Named Executive Officers” or “NEOs”), including the key factors that the Compensation Committee considered.

Our Named Executive Officers for fiscal 2023 were:

Executive Summary

Our executive compensation program is designed to attract, motivate, and retain key leaders responsible for our success. Our overall program structure and 2023 compensation decisions are designed to meet our pay for demonstrable performance objectives and align with stockholders’ long-term interests. In addition, our compensation actions during 2023 also included arrangements to support our CEO Transition.

Leadership Transition

Immediately following the termination of Odilon Almeida as our President and CEO in November 2022, Thomas Warsop III, formerly the non-executive Chair of the Company’s Board, became our interim President and CEO and we immediately commenced a comprehensive search process to identify a permanent CEO. We structured Mr. Warsop III’s compensation for this interim service to be simple, flexible (to address the unknown length of his tenure as interim CEO) and aligned with market comparables. Accordingly, for his interim service Mr. Warsop III received $325,000 per month and received a $325,000 discretionary bonus based on certain performance criteria at the end of his tenure as interim CEO. Subsequently, after the completion of its comprehensive search process, the Board appointed Mr. Warsop III as our full time CEO effective June 1, 2023.

2024 PROXY STATEMENT 31

Mr. Warsop III’s compensation as our full time CEO (effective June 1, 2023) is detailed below:

Ram Puppala’s employment as our Chief Technology Officer ceased effective June 30, 2023. On October 30, 2023, Mr. Kuruvilla joined the Company as our new Chief Technology Officer. The compensation that Mr. Kuruvilla received in connection with his commencement of employment is described below in this Compensation Discussion and Analysis.

Mr. Kuruvilla’s compensation was a result of negotiations, and was structured to be competitive and aligned with our executive compensation. His initial compensation consisted of a base salary rate of $460,000, a target bonus of 100% of base salary beginning with our 2024 fiscal year, an initial equity grant of approximately $1.6 million in RSUs (vesting annually over the three years following the grant date), and a sign-on bonus of $540,000 payable March 31, 2024 to address foregone compensation when he left his prior employer. His offer letter also provided that we would recommend a $2.2 million equity grant in 2024 as part of our annual grant cycle on the same terms as other executives.

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Performance Highlights

Adjusted EBITDA, Net Adjusted EBITDA Margin and Revenue Net of Interchange are non-GAAP financial measures. Adjusted EBITDA is defined as net income plus income tax expense (benefit), net interest income (expense), net other income (expense), depreciation, amortization and stock-based compensation, as well as significant transaction-related expenses. Revenue Net of Interchange is defined as revenue net of pass-through interchange revenue. Net Adjusted EBITDA Margin is defined as Adjusted EBITDA divided by Revenue Net of Interchange. For purposes of calculations under our 2023 short-term incentive program awards and our 2023 PSU awards, we further adjusted Adjusted EBITDA and Revenue Net of Interchange (including for purposes of calculating Net Adjusted EBITDA Margin) to be based on our 2023 budgeted foreign exchange rate rather than our actual foreign exchange rates.

See Appendix A for full reconciliation for Adjusted EBITDA, Net Adjusted EBITDA Margin and Revenue Net of Interchange, including as used for calculations under our 2023 short-term incentive program awards and our 2023 PSU awards.

2023 Compensation Highlights

Underlying our executive compensation program is a strong belief in promoting a pay-for-performance culture. To that end, the Compensation Committee designs the target total direct compensation of our executive officers so that a significant portion of the overall compensation opportunity is linked to our financial performance through our annual incentive plan and to our long-term financial performance through performance-based equity awards. In addition, the Compensation Committee sets challenging performance goals for each of the metrics used in our incentive compensation plans so that the amounts earned will be based upon successful performance as measured against pre-established financial, operational, and strategic objectives.

2024 PROXY STATEMENT 33

The pay mix of the target total direct compensation for our CEO and our other Named Executive Officers for 2023 reflects this pay-for-performance culture by ensuring that a significant amount of compensation is subject to performance or otherwise at risk.

Pay Mix

For fiscal 2023, we adjusted the financial metrics and weightings under both our annual incentive and long-term incentive plans. Our annual incentive plan continues to emphasize Adjusted EBITDA performance, weighted 40% for fiscal 2023 compared to 50% in the prior year. Consistent with our focus on revenue growth, we measure period-to-period growth of Revenue Net of Interchange (“Revenue Net of Interchange Growth”) performance, weighted 60%. We also added a critical incidents multiplier to focus management on reducing these potentially high-impact incidents year over year. With respect to our long-term incentive program, during fiscal 2023 we enhanced our award structure, which historically utilized only a relative total share return (“rTSR”) metric to determine payouts, to incorporate additional metrics tied to our key long-term strategic objectives. For 2023, we added Net Adjusted EBITDA Margin and Revenue Net of Interchange Growth as additional performance metrics for our long-term incentive awards as these are the key financial measures of our business performance. We continue to consider rTSR performance as a multiplier that can increase or decrease long-term incentive payouts by up to 20% based on performance over an approximately three year period. In 2024, we continued to refine the design of our performance share units (“PSUs”) to enhance their long term focus, as further described below in the section entitled “2024 Annual Equity Awards”.

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Annual Cash Incentive

2024 PROXY STATEMENT 35

Long-Term Incentive

2023 Long-Term Incentive Awards

Component		Proportion		How 2023 awards work		Vesting
PSUs				Based on ACI’s Revenue Net of Interchange Growth and Net Adjusted EBITDA Margin for three one-year periods; subject to a multiplier of +/- 20% based on rTSR for the three-year performance period versus the S&P MidCap 400 Index.		Three-year cliff vesting
RSUs				The ultimate value of an RSU is based on our stock price at the time of vesting, providing strong alignment with stockholders’ interests		Annually over 3 years for the CEO and quarterly over a three-year period for other NEOs

2021 PSU Payout

Stockholder Input on Executive Compensation Program

2023 Say-on-Pay Vote

At our 2023 annual meeting, our stockholders approved our named executive officer compensation, with approximately 94.5% of the votes cast in favor of our proposal. Shareholders have consistently given our executive compensation program approval in excess of 94% for each of the last 5 years. The Compensation Committee considered the 2023 vote outcome and determined that, based on the continued high level of approval, no significant changes were needed to the executive compensation program to address shareholder concerns.

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Stockholder Engagement and Feedback

In 2023, to continue our ongoing engagement with our stockholders, we reached out to stockholders representing over 65% of our outstanding shares. The purpose of the outreach was to discuss a range of ACI topics, including our executive compensation programs and to elicit feedback about what we are doing well and suggestions about what we can improve. Based on the feedback from our 2023 outreach, we do not believe that stockholders had significant concerns with the current executive compensation program. Stockholders are invited to express their views to the Compensation Committee as described under “Stockholder Communications with our Board” below.

Executive Compensation Philosophy and Practices

Our executive compensation program is guided by our overarching philosophy of paying for demonstrable performance. Consistent with this philosophy, we have designed our executive compensation program to achieve the following primary objectives:

We endeavor to maintain sound executive compensation policies, practices, and governance standards, consistent with our executive compensation philosophy, as summarized below.

2024 PROXY STATEMENT 37

Compensation Design

Overview

In alignment with our pay-for-performance philosophy, a significant portion of our Named Executive Officers’ target total direct compensation is “at-risk” and variable in the amount ultimately paid. We believe that linking a significant portion of our executive officers’ target total direct compensation to challenging performance objectives creates strong incentives for them to achieve our short-term profitability and growth objectives and to create sustainable long-term value for our stockholders. We believe that this approach also helps us attract talented individuals who are committed to achieving challenging goals with the opportunity to earn market competitive compensation if they and the Company demonstrate superior results.

Compensation Elements

Our executive compensation consists of three principal elements: base salary, an annual cash incentive compensation opportunity under the ACI STIP, and long-term compensation opportunities under the LTIP in the form of service-based RSUs and PSUs. Each of these elements is summarized in the table below. Although this Compensation Discussion and Analysis focuses on the compensation of our Named Executive Officers, our 2023 executive compensation program and our compensation-setting process (described below) were substantially the same for all our executive officers.

2024 PROXY STATEMENT 39

2023 Executive Compensation

Base Salary

Base salary represents the fixed portion of target total direct compensation and is intended to attract and retain highly talented individuals.

Each executive officer’s base salary, except our CEO’s, is based on the recommendation of our CEO to the Compensation Committee. These recommendations consider the various factors described above under “Compensation-Setting Process – Factors Considered in Compensation Deliberations.” The Compensation Committee, with the help of its compensation consultant, reviews the base salaries of our Named Executive Officers (other than our CEO) annually based on the CEO’s recommendation and the factors described above and adjusts the base salaries as it determines to be necessary or appropriate. Our Compensation Committee reviews the market data and proposes any adjustment for our CEO’s base salary to the independent members of our Board of Directors for approval.

The Compensation Committee reviewed the base salaries of our Named Executive Officers in December 2022 and January 2023.

Following this review, the Compensation Committee approved an increase to Mr. Silva’s, Mr. Behrens’, and Ms. Guerra’s salaries as part of our normal annual review process. The base salaries of our Named Executive Officers for 2022 and 2023 (after the effectiveness of the adjustments described above) were as follows:

Annual Cash Incentive Awards Under the STIP

Our STIP offers our Named Executive Officers the opportunity to earn short-term cash incentive awards based on our financial and operational performance and their individual performance as measured over a 12-month performance period. In March 2023, the Compensation Committee approved the terms of the 2023 STIP for our executive officers.

Annual Cash Incentive Award Opportunity Targets

At the beginning of each year, the Compensation Committee assigns each of our Named Executive Officers a target annual cash incentive award opportunity, the amount of which is calculated as a percentage of their annual base salary. These decisions take into account our CEO’s recommendations (except with respect to his incentive award opportunity), as well as the factors described under “Compensation-Setting Process – Factors Considered in Compensation Deliberations” above. Our Compensation Committee reviews the market data and determines any adjustment for our CEO’s target bonus.

In December 2022 and January 2023, the Compensation Committee reviewed the target annual cash incentive opportunities of our Named Executive Officers and determined not to change the target annual cash incentive compensation as a percentage of base salary for any of our continuing Named Executive Officers from the corresponding 2023 levels, where applicable. Increases in the dollar amount are a result of base salary increases. The decrease for Mr. Silva related to the ending of a legacy

2024 PROXY STATEMENT 41

sales incentive plan that he participated in prior to being promoted to CRO. The target annual cash incentive award opportunities of our Named Executive Officers for purposes of the 2022 STIP and the 2023 STIP were as follows:

Plan Terms – 2023 Performance Metrics

The 2023 STIP provided for a funding pool based on actual performance for the period beginning on January 1, 2023, and ending on December 31, 2023, as measured in two categories:

For our 2023 plan, we changed our revenue metric from revenue to Revenue Net of Interchange Growth. We made this change to align our performance goal with what we believe is a better measure of our financial performance, especially as our business continues to evolve. While our target for Revenue Net of Interchange Growth is shown as an absolute number rather than a percentage, we have set the threshold performance goal at last year’s actual Revenue Net of Interchange, so any payout is based on actual Revenue Net of Interchange Growth. In addition, we also added a multiplier to the funding pool tied to our reduction of critical incidents during the year, which was a key operational focus during 2023. The multiplier had the potential to increase the funding pool by up to 10% to the extent that we reduced the number of critical incidents by more than 10% as compared to fiscal 2022 levels and to reduce the funding pool by up to 20% if the number of critical incidents were higher than 2022. Final payout determinations for our executive officers could have been increased or decreased by up to 10% based on the CEO’s assessment of their individual performance (for executives other than himself). Payments under the 2023 STIP could have ranged from 0% to 200% of an executive’s target annual cash incentive award, depending on the Company’s and the executive officer’s actual performance for the year. However, the aggregate of all 2023 STIP payments could not have exceeded the aggregate pool funded for payouts for all participants based on corporate performance. The Compensation Committee believes this plan design aligns with our strategy of driving profitable growth, which is critical to shareholders and long-term success.

The 2023 performance goals for the two financial performance metrics are shown below.

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Plan Terms – Individual Performance

Payouts for a Named Executive Officer under the 2023 STIP could have been adjusted up or down by up to 10% based on the CEO’s subjective evaluation of individual job performance and recommendation to the Compensation Committee.

Annual Cash Incentive Awards – 2023 Results and Payouts

In February 2024, the Compensation Committee certified our 2023 performance and determined the amounts to be paid under the 2023 STIP. 2023 Adjusted EBITDA was $396.3 million, which resulted in a formulaic payout percentage to all the Named Executive Officers of 131.7% of their target annual cash incentive awards with respect to such metric. 2023 Revenue Net of Interchange was $1,031.1 million, which resulted in a formulaic payout percentage to all of the Named Executive Officers of 94.8% of each of their target annual cash incentive awards with respect to such metric. The combined overall STIP payout percentage for Company performance based on the formula was 109.5% of target. We reduced the number of critical incidents in 2023 by more than 10% as compared to fiscal 2022 levels, which resulted in a multiplier to our corporate results of 10% and a total bonus payout percentage of 120.5%. For 2023, the CEO recommended, and the Compensation Committee approved, a 5% increase in the STIP payout for our CFO to recognize his exceptional performance in managing the action plans required to achieve our results. This resulted in a STIP payout of 126.5% for him. None of the other Named Executive Officers received an individual adjustment to their STIP payouts, so the corporate performance, including the critical incidents modifier of +10%, resulted in a payout of 120.5% of each of their target bonuses to determine their 2023 STIP payout.

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As noted above, for 2023, our CEO, recommend a 5% increase to the STIP payout for our CFO. None of our other NEOs received a modification based on individual performance. The payouts are shown in the table below.

Bonus Award – Interim CEO

As part of his compensation arrangement for service as our interim CEO (for periods prior to June 1, 2023), Mr. Warsop III was entitled to a bonus at the end of his interim service of $325,000, at the discretion of our Board of Directors based on their evaluation of his performance. Our Board of Directors determined that Mr. Warsop III had earned the full $325,000 bonus when he completed his interim service and was appointed our full time CEO.

Sales Incentive Plan – 2023 Results and Payouts

For 2023, in addition to an award under the STIP, Mr. Silva was also eligible for awards under a sales incentive plan. His award opportunity was $210,000, which was 50% of his base salary at the beginning of 2023, when the sales incentive plan was set. His sales incentive plan was composed of three metrics: (i) annual recurring revenue; (ii) license revenue from sales and services; and (iii) total revenue. He earned approximately 80% of target, or $169,035, from the sales incentive plan. None of the other Named Executive Officers is eligible for an award under the sales incentive plan.

Long-Term Incentive Compensation

Our LTIP provides for the grant of equity awards to our NEOs, executive officers and other key employees whose responsibilities and decisions directly impact our long-term business results. We use equity awards to incentivize these individuals and in other circumstances that may arise from time to time, such as promotions and new hire arrangements. Our equity award grant practices are designed to balance four priorities: (1) our desire to motivate and retain executive talent, (2) our belief in the benefits that accrue to ACI when we align the interests of our management team with those of our stockholders, (3) our need to remain competitive in recruiting, and (4) our need to effectively manage the dilution of stockholders’ interests.

In May 2023, the Compensation Committee granted regular annual long-term incentive awards to our Named Executive Officers, other than our CEO, divided equally between RSUs and PSUs that may be earned, if at all, based on our Revenue Net of Interchange Growth, Net Adjusted EBITDA Margin, and the total shareholder return of our common stock relative to the S&P MidCap 400 Index (rTSR). The Compensation Committee believes this balance of time-based and performance-based equity incentivizes performance and promotes retention. In connection with our CEO’s appointment as our full time CEO in June 2023, the Compensation Committee granted the CEO a 2023 long-term incentive award with a target value of $4 million of which 65% was composed of PSUs and the remaining 35% was composed of RSUs.

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Annual Equity Awards for 2023

Typically, the size and form of the equity awards for our executive officers are determined in the discretion of the Compensation Committee based on the recommendation of our CEO (except with respect to his own equity award). Among other things, the Compensation Committee considers the values that are competitive with current market conditions using our compensation consultant’s analysis of competitive market data, the proportion of our total shares outstanding used for annual employee long-term incentive compensation awards (our “burn rate”) in relation to that of the companies in our compensation peer group, the potential dilution to our stockholders (our “overhang”) in relation to the median practice of the companies in our compensation peer group, and the other factors described under “Compensation-Setting Process – Factors Considered in Compensation Deliberations” above.

For 2023, we evolved the design of our PSU awards, which previously were based solely on the total shareholder return of our common stock relative to the S&P 400 MidCap Index, to focus our executives on top-line Revenue Net of Interchange Growth and bottom-line Net Adjusted EBITDA Margin performance, which we consider to be key measures of our financial success that are largely within management’s direct control. We continued to incorporate total shareholder return as a multiplier, which provides strong upside potential in the event of outperformance relative to the competitive market over an approximately three-year performance period and provides a meaningful incentive even in a down market if we achieve strong relative performance. In addition, consideration of rTSR performance provides a direct link between compensation and stockholder return, thereby motivating our executive officers to focus on and strive to achieve both our annual and long-term business objectives. The Compensation Committee selected the S&P 400 MidCap Index as a reference point because it tracks the investment results of similarly sized U.S. public companies and ACI was a constituent at the time of the grant.

The target grant date fair values of the 2023 regular annual equity awards for our participating Named Executive Officers increased marginally as reflected in the table below to align with market practices for similar positions, to reflect the performance of the Named Executive Officers and the Company during the prior year, and to emphasize long-term performance-based compensation for our top executives. Ms. Guerra’s year-over-year increase reflects her increased responsibilities following her promotion in July 2022.

The target value annual equity awards granted to our Named Executive Officers, including the initial award to Messrs Warsop III and Kuruvilla, in 2023 were as follows: