Exhibit 3.1

AMENDED AND RESTATED

CERTIFICATE OF INCORPORATION

OF

S1 CORPORATION

FIRST: The name of the corporation (the “Corporation”) is S1 Corporation.

SECOND: The address of the Corporation’s registered office in the State of Delaware is 1209 Orange Street, City of Wilmington, County of New Castle, Delaware 19801. The name of the Corporation’s registered agent at such address is The Corporation Trust Company.

THIRD: The purpose of the Corporation is to engage in any lawful act or activity for which corporations may be organized under the General Corporation Law of the State of Delaware.

FOURTH: The total number of shares which the Corporation shall have authority to issue is 1,000 shares of Common Stock, par value of $0.01 per share.

FIFTH: Elections of directors need not be by written ballot except and to the extent provided in the bylaws of the Corporation.

SIXTH: To the full extent permitted by the General Corporation Law of the State of Delaware or any other applicable laws presently or hereafter in effect, no director of the Corporation shall be personally liable to the Corporation or its stockholders for or with respect to any acts or omissions in the performance of his or her duties as a director of the Corporation. Any repeal or modification of this Article Sixth shall not adversely affect any right or protection of a director of the Corporation existing immediately prior to such repeal or modification.

SEVENTH: (a) To the extent permitted by law, the Corporation shall fully indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding (whether civil, criminal,

administrative or investigative) by reason of the fact that such person is or was a director or officer of the Corporation, or is or was serving at the request of the Corporation as a director or officer of another corporation, partnership, joint venture, trust, employee benefit plan or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding.

(b) To the extent permitted by law, the Corporation may fully indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding (whether civil, criminal, administrative or investigative) by reason of the fact that such person is or was an employee or agent of the Corporation, or is or was serving at the request of the Corporation as an employee or agent of another corporation, partnership, joint venture, trust, employee benefit plan or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding.

(c) The Corporation may advance expenses (including attorneys’ fees) incurred by a director or officer in advance of the final disposition of such action, suit or proceeding upon the receipt of an undertaking by or on behalf of the director or officer to repay such amount if it shall ultimately be determined that such director or officer is not entitled to indemnification. The Corporation may advance expenses (including attorneys’ fees) incurred by an employee or agent in advance of the final disposition of such action, suit or proceeding upon such terms and conditions, if any, as the Board of Directors deems appropriate.

EIGHTH: In furtherance and not in limitation of the rights, powers, privileges, and discretionary authority granted or conferred by the General Corporation Law of the State of Delaware or other statutes or laws of the State of Delaware, the Board of Directors is expressly authorized to make, alter, amend or repeal the bylaws of the Corporation,

without any action on the part of the stockholders, but the stockholders may make additional bylaws and may alter, amend or repeal any bylaw whether adopted by them or otherwise. The Corporation may in its bylaws confer powers upon its Board of Directors in addition to the foregoing and in addition to the powers and authorities expressly conferred upon the Board of Directors by applicable law.

NINTH: The Corporation reserves the right at any time and from time to time to amend, alter, change or repeal any provision contained in this Amended and Restated Certificate of Incorporation, and other provisions authorized by the laws of the State of Delaware at the time in force may be added or inserted, in the manner now or hereafter prescribed herein or by applicable law; and all rights, preferences and privileges of whatsoever nature conferred upon stockholders, directors or any other persons whomsoever by and pursuant to this Amended and Restated Certificate of Incorporation in its present form or as hereafter amended are granted subject.