<PAGE>
 
                                                                     EXHIBIT 3.1


                     RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                                 BANCTEC, INC.

                           Under Sections 242 and 245
                                     of the
                        Delaware General Corporation Law


     We, G. Wesley Mayland, Senior Vice President and Tod V. Mongan, Secretary
of BancTec, Inc., a corporation existing under the laws of the State of
Delaware, do hereby certify under the seal of such corporation as follows:

     FIRST:  That the name of the corporation is BancTec, Inc.

     SECOND:   That the Certificate of Incorporation of the corporation was
filed by the Secretary of State of Del aware on January 2, 1987, under the name
of BancTec-Delaware, Inc.

     THIRD:    The amendments and the restatement of the Certificate of
Incorporation have been duly adopted in accordance with the provisions of the
General Corporation Law of the State of Delaware by an affirmative vote of the
holders of a majority of all outstanding shares entitled to vote at a meeting of
stockholders.

     FOURTH:   That the text of the Certificate of Incorporation of BancTec,
Inc. , as amended, is hereby restated as further amended by this certificate, to
read in full, as follows:
<PAGE>
 
                     RESTATED CERTIFICATE OF INCORPORATION
                                      OF
                                 BANCTEC, INC.



     FIRST:    The name of the Corporation is BancTec, Inc.

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

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

     FOURTH:   The aggregate number of shares which the Corporation shall have
authority to issue is 15, 000, 000 shares, $.01 par value, designated Common
Stock and 1,000,000 shares, $. 01 value, designated Preferred Stock.  The
following is a statement of the designations, preferences, limitations, and
relative rights in respect of the shares of each class of stock of the
Corporation.

                               A. PREFERRED STOCK

     Shares of the Preferred Stock may be issued from time to time in one or
     more series, the shares of each series to have such voting powers, full or
     limited, or no voting powers, and such designations, preferences and
     relative, participating, optional or other special rights, and
     qualifications, limitations or restrictions thereof, as shall be stated and
     expressed in a resolution or resolutions providing for the issue of such
     series adopted by the board of directors of the Corporation.  The board of
     directors of the Corporation is hereby expressly authorized to establish
     and designate series of the Preferred Stock, to fix the number of shares
     constituting each series, and to fix the designations and the powers,
     rights, preferences, qualifications, limitations, and restrictions of the
     shares of each series and the variations of the relative powers, rights,
     preferences, qualifications, limitations, and restrictions as between
     series, and to increase and to decrease the number of shares constituting
     each series.

                                       2
<PAGE>
 
                                B. COMMON STOCK

     1. Subject to the prior rights and preferences of the Preferred Stock and
     subject to the provisions and on the conditions set forth in the foregoing
     part A of this ARTICLE FOURTH, or in any resolution or resolutions
     providing for the issue of a series of Preferred Stock, such dividends
     (payable in cash, stock, or otherwise) as may be determined by the board of
     directors may be declared and paid on the Common Stock from time to time
     out of any funds legally available therefor.

     2.  The shares of Common Stock shall be fully voting stock at the rate of
     one vote for each share of Common Stock held.

     3.  After payment shall have been made in full to the holders of the
     Preferred Stock in the event of any liquidation, dissolution, or winding up
     of the affairs of the Corporation, the remaining assets and funds of the
     Corporation shall be distributed among the holders of the Common Stock
     according to their respective shares.

     FIFTH:    No director of the Corporation shall be personally liable to the
Corporation or its shareholders for monetary damages for breach of fiduciary
duty as a director, except for liability (i) for any breach of the director's
duty of loyalty to the Corporation or its shareholders, (ii) for acts or
omissions not in good faith or which involve intentional misconduct or a knowing
violation of law, (iii) under Section 174 of the Delaware General Corporation
Law, or (iv) for any transaction from which the director derived an improper
personal benefit.

     SIXTH:    Directors of the Corporation need not be elected by written
ballot unless the Bylaws of the Corporation otherwise provide.

     SEVENTH:  The directors of the Corporation shall have the power to adopt,
amend, and repeal the Bylaws of the Corporation.

     EIGHTH:   No contract or transaction between the Corporation and one or
more of its directors, officers, or shareholders or between the Corporation and
any person (as used herein "person" means other corporation, partnership,
association, firm, trust, joint venture, political subdivision, or
instrumentality) or other organization in which one or more of its directors,
officers, or shareholders are directors, officers or shareholders, or have a
financial interest, shall be void or voidable solely for this reason, or solely
because the director or officer is present at or participates in the meeting of
the 

                                       3
<PAGE>
 
board or committee which authorizes the contract or transaction, or solely
because his or their votes are counted for such purpose, if: (1) the material
facts as to his relationship or interest and as to the contract or transaction
are disclosed or are known to the board of directors or the committee, and the
board of directors or committee in good faith authorizes the contract or
transaction by the affirmative votes of a majority of the disinterested
directors, even though the disinterested directors be less than a quorum; or (2)
the material facts as to his relationship or interest and as to the contract or
transaction are disclosed or are known to the shareholders entitled to vote
thereon, and the contract or transaction is specifically approved in good faith
by vote of the shareholders; or (3) the contract or transaction is fair as to
the Corporation as of the time it is authorized, approved or ratified by the
board of directors, a committee thereof, or the shareholders. Common or
interested directors may be counted in determining the presence of a quorum at a
meeting of the board of directors or of a committee which authorizes the
contract or transaction.

     NINTH:    Section 1.  The number of directors of the Corporation, and the
number of directors in each class, shall be fixed from time to time by or
pursuant to the Bylaws of the Corporation but the number of directors of the
Corporation shall not be less than three or more than fifteen.  The directors
shall be divided into three classes, as nearly equal in number as possible, as
shall be provided in the Bylaws of the Corporation. Unless otherwise provided in
the Bylaws, at the annual meeting of stockholders held in 1987, one class.of
three directors shall be elected for a term expiring at the annual meeting of
stockholders to be held in 1988, another class of three directors shall be
elected for a term expiring at the annual meeting of stockholders to be held in
1989 and another class of three directors shall be elected for a term expiring
at the annual meeting of stockholders to be held in 1990, with each class to
hold office until its successors are elected and qualified.  At each annual
meeting of stockholders subsequent to 1987, the successors of the class of
directors whose term expires at that meeting shall be elected to hold office for
a term expiring at the annual meeting of stockholders held in the third year
following the year of their election.  The election of directors need not be by
written ballot.  No decrease in the number of directors constituting the Board
of Directors shall shorten the term of any incumbent director.

     Section 2.  Except as otherwise provided for or fixed by or pursuant to any
other provisions of the Certificate of Incorporation relating to the rights of
the holders of any class or series of stock having a preference over the Common
Stock as to dividends or upon liquidation, newly created directorships resulting
from any increase in the number of directors and any vacancies on the Board of
Directors resulting from death, 

                                       4
<PAGE>
 
resignation, removal or other cause shall only be filled by the affirmative vote
of a majority of the remaining directors then in office, even though less than a
quorum of the Board of Directors, or by a sole remaining director. Any director
elected in accordance with the preceding sentence of this Section 2 shall hold
office for the remainder of the full term of the class of directors in which the
new directorship was created or the vacancy occurred and until such director' s
successor shall have been elected and qualified.

     Section 3.  Subject to the rights of the holders of the Preferred Stock or
any other class or series of stock having a preference over the Common Stock as
to dividends or upon liquidation, any director may be removed from office only
for cause and only by the affirmative vote of the holders of a -majority of the
combined voting power of the then outstanding shares of Voting Stock, voting
together as a single class.  For purposes of this Section 3, "cause" shall mean
the willful and continuous failure of a director to substantially perform such
director' s duties to the Corporation (other than any such failure resulting
from incapacity due to physical or mental illness) or the willful engaging by a
director in gross misconduct materially and demonstrably injurious to the
Corpora%ion.

     Section 4.  Notwithstanding any other provisions of this Certificate of
Incorporation, the provisions set forth in this Article Ninth may not be
repealed or amende& in any respect, and no article imposing cumulative voting in
the election of directors may be added, unless such action is approved by the
affirmative vote of the holders of voting shares entitling them to exercise not
less than two-thirds of the total voting power of all outstanding voting shares
of this Corporation, subject to the provisions of any series of Preferred Stock
which may at the time be outstanding.

     TENTH:    The Corporation shall indemnify any person who was, is, or is
threatened to be made a party to a proceeding (as hereinafter defined) by reason
of the fact that he (i) is or was a director or officer of the Corporation or
(ii) while a director or officer of the Corporation, is or was serving at the
request of the Corporation as a director, officer, partner, venturer,
proprietor, trustee, employee, agent, or similar functionary of another foreign
or domestic corporation, partnership, joint venture, sole proprietors hip,
trust, employee benefit plan, or other enterprise, to the fullest extent
permitted under the Delaware General Corporation Law, as the same exists or may
hereafter be amended.  Such right shall be a contract right and shall include
the right to be paid by the Corporation expenses incurred in defending any such
proceeding in advance of its final disposition to the maximum extent permitted
under the Delaware General Corporation Law, as the same exists or may hereafter
be amended.  If a claim for indemnification or advancement of 

                                       5
<PAGE>
 
expenses hereunder is not paid in full by the Corporation within 60 days after a
written claim has been received by the Corporation, the claimant may at any time
thereafter bring suit against the Corporation to recover the unpaid amount of
the claim, and if successful in whole or in part, the claimant shall also be
entitled to be paid the expenses of prosecuting such claim. It shall be a
defense to any such action that such indemnification or advancement of costs of
defense are not permitted under the Delaware General Corporation Law, but the
burden of providing such defense shall be on the Corporation. Neither the
failure of the Corporation (including its board of directors or any committee
thereof, independent legal counsel, or shareholders) to have made its
determination prior to the commencement of such action that indemnification of,
or advancement of costs of defense to, the claimant is permissible in the
circumstances nor an actual determination by the Corporation (including its
board of directors or any committee thereof, independent legal counsel, or
shareholders) that such indemnification or advancement is not permissible shall
be a defense to the action or create a presumption that such indemnification or
advancement is not permissible. In the event of the death of any person having a
right of indemnification under the foregoing provisions, such right shall inure
to the benefit of his heirs, executors, administrators, and personal
representatives. The rights conferred above shall not be exclusive of any other
right which any person may have or hereafter acquire under any statute, bylaw,
resolution of shareholders or directors, agreement, or otherwise.

     The Corporation may additionally indemnify any employee or agent of the
Corporation to the fullest extent permitted by law.

     As used herein, the term "proceeding" means any threatened, pending, or
completed action, suit, or proceeding, whether civil, criminal, administrative,
arbitrative, or investigative, any appeal in such an action, suit, or
proceeding, and any inquiry or investigation that could lead to such an action,
suit, or proceeding.

     ELEVENTH: Whenever a compromise or arrangement is proposed between the
Corporation and its creditors or any class of them and/or between the
Corporation and its shareholders or any class of them, any court of equitable
jurisdiction within the State of Delaware may, on the application in a summary
way of the Corporation or of any creditor or shareholder thereof or on the
application of any receiver or receivers appointed for the Corporation under the
provisions of section 291 of Title 8 of the Delaware Code or on the application
of trustees in dissolution or of any receiver or receivers appointed for the
Corporation under the provisions of section 279 of Title 8 of the Delaware Code,
order a meeting of the creditors or class of creditors and/or of the
shareholders or class of shareholders of the Corporation, as 

                                       6
<PAGE>
 
the case may be, to be summoned in such manner as the said court directs. If a
majority in number representing three-fourths in value of the creditors or class
of creditors and/or of the shareholders or class of shareholders of the
Corporation, as the case may be, agree to any compromise or arrangement and to
any reorganization of the Corporation as a consequence of such compromise or
arrangement, the said compromise or arrangement and the said reorganization
shall, if sanctioned by the court to which the said application has been made,
be binding on all the creditors or class of creditors, and/or on all the
shareholders or class of shareholders, of the Corporation, as the case may be,
and also on the Corporation.

     IN WITNESS WHEREOF, we have signed this certificate and caused the
corporate seal of the corporation to be hereunto affixed as of the 13th day
of April, 1988.

                              /s/ G. Wesley Mayland
                              ---------------------
                              G. Wesley Mayland,
                              Senior Vice President

     CORPORATE SEAL



Attest:


/s/ Tod V. Mongan
------------------------
Tod V. Mongan, Secretary

                                       7
<PAGE>
 
STATE OF TEXAS      (S)
                    (S)
COUNTY OF DALLAS    (S)

     Be if remembered that on this 13th day of April, 1988, personally came
before me Debra Jean Hill, notary public in and for the county and state
aforesaid, G. Wesley Mayland, a party to the foregoing certificate, known to me
personally to be such, and duly acknowledged such certificate to be his act and
deed, and that the facts therein stated are true.

     Given under my hand and seal of office the day and year aforesaid.



                                    /s/ Debra Jean Hill
                                    ----------------------------
                                    Notary Public in and for the
                                           State of Texas
NOTARY PUBLIC    DEBRA JEAN HILL
STATE OF TEXAS   Notary Public      My Commission Expires:  7/8/90
                 STATE OF TEXAS

                 My Comm. Exp. July 8, 1990

                                    



STATE OF TEXAS      (S)
                    (S)
COUNTY OF DALLAS    (S)



     Be if remembered that on this 13th day of April, 1988, personally came
before me Debra Jean Hill, a notary public in and for the county and state
aforesaid, Tod V. Mongan, a party to the foregoing certificate, known to me
personally to be such, and duly acknowledged such certificate to be his act and
deed, and that the facts therein stated are true.

     Given under my hand and seal of office the day and year aforesaid.


                                    /s/ Debra Jean Hill
                                    ----------------------------
                                    Notary Public in and for the
                                           State of Texas
NOTARY PUBLIC    DEBRA JEAN HILL
STATE OF TEXAS   Notary Public      My Commission Expires:  7/8/90
                 STATE OF TEXAS

                 My Comm. Exp. July 8, 1990

                                       8
<PAGE>
 

                           CERTIFICATE OF AMENDMENT
                                      TO
                         CERTIFICATE OF INCORPORATION
                                      OF
                                 BANCTEC, INC.

     BancTec, Inc., a corporation organized and existing under and by virtue of 
the General Corporation Law of the State of Delaware (the "Corporation"), does 
hereby certify:

     FIRST: That, at a meeting of the Board of Directors of the Corporation, 
resolutions were duly adopted setting forth proposed amendments to the 
Certificate of Incorporation of the Corporation, declaring said amendments to be
advisable and calling a meeting of the stockholders of the Corporation for 
consideration thereof. The resolutions setting forth the proposed amendments are
as follows:

     RESOLVED, THAT THE CORPORATION AMEND ITS CERTIFICATE OF INCORPORATION AS ON
     FILE WITH THE SECRETARY OF STATE OF DELAWARE TO AMEND THE FIRST SENTENCE OF
     ARTICLE FOURTH OF ITS CERTIFICATE OF INCORPORATION TO READ IN ITS ENTIRETY
     AS SET FORTH BELOW:

                                    FOURTH:

     "The total number of shares of stock which the Corporation shall have 
authority to issue is 46,000,000 shares, divided into two classes as follows: 
(i) 1,000,000 shares of Preferred Stock, par value $.01 per share; and (ii) 
45,000,000 shares of Common Stock, par value $.01 per share."

     RESOLVED, THAT THE CORPORATION AMEND ITS CERTIFICATE OF INCORPORATION AS ON
     FILE WITH THE SECRETARY OF STATE OF DELAWARE TO ADD A NEW ARTICLE TO ITS
     CERTIFICATE OF INCORPORATION, WHICH NEW ARTICLE SHALL BE ARTICLE TWELFTH
     AND SHALL READ IN ITS ENTIRETY AS SET FORTH BELOW:

                                   TWELFTH:

     "I. The affirmative vote of the holders of not less than seventy-five 
percent (75%) of the outstanding shares of "Voting Stock" (as hereinafter 
defined) shall be required to consummate or effect any "Business Combination" 
(as hereinafter defined) involving the Corporation or any "Subsidiary" (as 
hereinafter defined) of the Corporation and any "Related Person" (as

<PAGE>
 
hereinafter defined), or any "Affiliate" or "Associate" (as hereinafter defined)
of a Related Person, notwithstanding the fact that no vote may be required or 
that a lesser percentage may be specified by law, in any agreement with any 
national securities exchange or otherwise; provided, however, that the 
seventy-five percent (75%) voting requirement shall not be applicable and such 
Business Combination shall require only such affirmative vote as is required by 
law, any agreement with any national securities exchange or otherwise if:

          (1) The Business Combination shall have been approved by the Board of
     Directors without counting the vote of any director who is not a
     "Disinterested Director" (as hereinafter defined); or

          (2) All of the following conditions are met:

               (i) The aggregate amount of cash or the "Fair Market Value" (as
          hereinafter defined) as of the date of the consummation of the
          Business Combination (the "Combination Date") of the property,
          securities or other consideration to be received per share by holders
          of a particular class or series of capital stock, as the case may be,
          of this Corporation in the Business Combination is not less than the
          highest of:

                    (a) the highest per share price (including brokerage
               commissions, transfer taxes and soliciting dealers' fees) paid by
               or on behalf of the Related Person in acquiring beneficial
               ownership of any of its holdings of such class or series of
               capital stock of this Corporation (A) within the two-year period
               immediately prior to the first public announcement of the
               proposed Business Combination (the "Announcement Date") or (B) in
               the transaction or series of transactions in which the Related
               Person became a Related Person, whichever is higher; or

                    (b) the Fair Market Value per share of the shares of capital
               stock being acquired in the Business Combination as of (A) the
               Announcement Date or (B) the date on which the Related Person
               became a Related Person, whichever is higher; or

                    (c) in the case of shares of Common Stock, the per share
               book value of the Common Stock as reported at the end of the
               fiscal quarter immediately prior to the Announcement Date, and in
               the case of shares of Preferred Stock, the highest preferential
               amount per share to which the holders of shares of such class or
               series of Preferred

                                       2

<PAGE>
 
               Stock would be entitled as of the Combination Date in the event
               of any voluntary or involuntary liquidation, dissolution or
               winding up of the affairs of the Corporation, regardless of
               whether the Business Combination to be consummated constitutes
               such an event.

                    The provisions of this paragraph I(2)(i) shall be required
               to be met with respect to every class or series of outstanding
               capital stock, whether or not the Related Person has previously
               acquired any shares of a particular class or series of capital
               stock. In all of the above instances, appropriate adjustments
               shall be made for recapitalizations and for stock dividends,
               stock splits and like distributions; and

               (ii) The consideration to be received by holders of a particular 
          class or series of capital stock shall be in cash or in the same form
          as previously has been paid by or on behalf of the Related Person in
          connection with its direct or indirect acquisition of beneficial
          ownership of shares of such class or series of stock. If the
          consideration so paid for any such share varied as to form, the form
          of consideration for such shares shall be either cash or the form used
          to acquire beneficial ownership of the largest number of shares of
          such class or series of capital stock previously acquired by the
          Related Person; and

               (iii) After such Related Person has become a Related Person and
          prior to the consummation of such Business Combination: (a) except as
          approved by the Board of Directors without counting the vote of any
          director who is not a Disinterested Director, there shall have been no
          failure to declare and pay at the regular date therefor any full
          quarterly dividends (whether or not cumulative) on the outstanding
          Preferred Stock; (b) there shall have been (A) no reduction in the
          annual rate of dividends paid on the Common Stock (except as necessary
          to reflect any subdivision of the Common Stock), except as approved by
          the Board of Directors without counting the vote of any director who
          is not a Disinterested Director, and (B) an increase in such annual
          rate of dividends as necessary to reflect any reclassification
          (including any reverse stock split), recapitalization, reorganization
          or any similar transaction which has the effect of reducing the number
          of outstanding shares of the Common Stock, unless the failure so to
          increase such annual rate is approved by the Board of Directors
          without counting the vote of any director who is not a

                                       3

<PAGE>
 
     Disinterested Director; and (c) such Related Person shall not have become
     the beneficial owner of any additional shares of Voting Stock except as
     part of the transaction which results in such Related Person becoming a
     Related Person; and

          (iv) After such Related Person has become a Related Person, such
     Related Person shall not have received the benefit, directly or indirectly
     (except proportionately as a stockholder), of any loans, advances,
     guarantees, pledges or other financial assistance or any tax credits or
     other tax advantages provided by the Corporation, whether in anticipation
     of or in connection with such Business Combination or otherwise; and

          (v) A proxy or information statement describing the proposed Business
     Combination and complying with the requirements of the Securities Exchange
     Act of 1934, as amended, and the rules and regulations thereunder (the
     "Exchange Act") (or any provisions subsequently replacing the Exchange Act,
     rules or regulations) shall be mailed to all stockholders of the Company at
     least 30 days prior to the consummation of such Business Combination
     (whether or not such proxy or information statement is required to be
     mailed pursuant to the Exchange Act or subsequent provisions).

II.  For purposes of this Article TWELFTH:

     (1) The term "Business Combination" shall mean any (i) merger or 
consolidation of the Corporation or a Subsidiary of the Corporation with a 
Related Person or any other corporation which is or after such merger or 
consolidation would be an Affiliate or Associate of a Related Person; (ii) sale,
lease, exchange, mortgage, pledge, transfer or other disposition (in one 
transaction or a series of transactions) to or with any Related Person or any 
Affiliate or Associate of any Related Person, of any assets of the Corporation 
or of a Subsidiary of the Corporation having an aggregate Fair Market Value of 
10% or more of the total consolidated assets of the Corporation and its 
Subsidiaries taken as a whole, as of the end of its most recent fiscal year 
ending prior to the time the determination is being made; (iii) sale, lease, 
exchange, mortgage, pledge, transfer or other disposition (in one transaction of
a series of transactions), to the Corporation or a Subsidiary of the Corporation
of any assets of a Related Person or any Affiliate or Associate of any Related 
Person having an aggregate Fair Market value of 10% or more of the total 
consolidated assets of the Corporation and its Subsidiaries taken as a whole, as
of the end of its most
               
                                       4

<PAGE>
 
recent fiscal year ending prior to the time the determination is being made; 
(iv) issuance, pledge or transfer of securities of the Corporation or a 
Subsidiary of the Corporation (in one transaction or a series of transactions) 
to or with a Related Person or any Affiliate or Associate of any Related Person;
(v) reclassification of securities (including any reverse stock split) or 
recapitalization of the Corporation, or any merger or consolidation of the 
Corporation with any of its Subsidiaries or any other transaction (whether or 
not with or into or otherwise involving a Related Person or any Affiliate or 
Associate of any Related Person) that would have the effect, either directly or 
indirectly, of increasing the proportionate share of any class of equity or 
convertible securities of the Corporation or any Subsidiary of the Corporation 
which is directly or indirectly beneficially owned by any Related Person or any 
Affiliate or Associate of any Related Person; (vi) the adoption of any plan or 
proposal for the liquidation or dissolution of the Corporation proposed by or on
behalf of a Related Person or any Affiliate or Associate thereof; or (vii) any 
agreement, contract or other arrangement providing for or resulting in any of 
the transactions described in this definition of Business Combination.

     (2) The term "person" shall mean any individual, firm, corporation or other
entity and shall include any group comprised of any person and any other person
with whom such person or any Affiliate or Associate of such person has any
agreement, arrangement or understanding, directly or indirectly, for the purpose
of acquiring, holding, voting or disposing of Voting Stock of the Corporation.

     (3) The term "Related Person" shall mean any person (other than the
Corporation, or any Subsidiary and other than any profit-sharing, employee stock
ownership or other employee benefit plan of the Corporation or any Subsidiary or
any trustee of or fiduciary with respect to any such plan when acting in such
capacity) who or which:

          (i) is the beneficial owner (as hereinafter defined) of 20 percent 
     (20%) or more of the Voting Stock;

          (ii) is an Affiliate or Associate of the Corporation and at any time
     within the two-year period immediately prior to the date in question was
     the beneficial owner of 20 percent (20%) or more of the then outstanding
     Voting Stock; or

          (iii) is an assignee of or has otherwise succeeded to the beneficial 
     ownership of any shares of Voting

                                       5

<PAGE>
 
     Stock which were at any time within the two-year period immediately prior
     to such time beneficially owned by any Related Person, if such assignment
     or succession shall have occurred in the course of a transaction or series
     of transactions not involving a public offering within the meaning of the
     Securities Act of 1933, as amended.

     (4) A person shall be a "beneficial owner" of any Voting Stock:

          (i) which such person or any of its AFfiliates or Associates 
     beneficially owns, directly or indirectly;

          (ii) which such person or any of its Affiliates or Associates has,
     directly or indirectly, (a) the right to acquire (whether such right is
     exercisable immediately or only after the passage of time), pursuant to any
     agreement, arrangement or understanding or upon the exercise of conversion
     rights, exchange rights, warrants or options, or otherwise, or (b) the
     right to vote pursuant to any agreement, arrangement or understanding; or

          (iii) which are beneficially owned, directly or indirectly, by any
     other person with which such person or any of its Affiliates or Associates
     has any agreement, arrangement or understanding for the purpose of
     acquiring, holding, voting or disposing of any shares of Voting Stock.

     (5) For the purposes of determining whether a person is a Related Person 
pursuant to subparagraph (3) of this paragraph II, the number of shares of 
Voting Stock deemed to be outstanding shall include shares deemed owned through 
application of subparagraph (4) of this paragraph II but shall not include any 
other shares of Voting Stock which may be issuable pursuant to any agreement, 
arrangement or understanding, or upon exercise of conversion rights, warrants or
options, or otherwise.

     (6) The term "Affiliate" and "Associate" shall mean the respective meanings
ascribed to such terms in Rule 12b-2 of the General Rules and Regulations under 
the Exchange Act as in effect at the date of the adoption of this Article 
TWELFTH by the stockholders of the Company.

     (7) The term "Subsidiary" means any corporation of which a majority of any
class of equity securities is owned, directly or indirectly, by the Corporation;
provided, however, that for the purposes of the definition of Related Person set
forth in subparagraph (3) of this paragraph II,

                                       6

<PAGE>
 
the term "Subsidiary" shall mean only a corporation of which a majority of each 
class of equity securities is owned, directly or indirectly, by the Corporation.

     (8) The term "Disinterested Director" means any member of the Board of 
Directors, while such person is a member of the Board of Directors, who is not 
an Affiliate, Associate or a representative of the Related Person involved in a 
proposed Business Combination and was a member of the Board of Directors prior 
to the time that the Related Person became a Related Person, and any successor 
of a Disinterested Director, while such successor is a member of the Board of 
Directors, who is not an Affiliate, Associate or a representative of the Related
Person and is recommended or elected to succeed a Disinterested Director by the 
Board of Directors without counting the vote of any director who is not a 
Disinterested Director.

     (9) For the purposes of paragraph I(2)(i) of this Article TWELFTH, the term
"other consideration to be received" shall include, without limitation, capital 
stock retained by the stockholders.

     (10) The term "Voting Stock" shall mean all of the outstanding shares of 
capital stock of the Corporation entitled to vote generally in the election of 
directors, and each reference to a proportion of shares of Voting Stock shall 
refer to such proportion of the voters entitled to be cast by such shares voting
as one class (it being understood that for the purposes of this Article TWELFTH,
each share of Voting Stock shall have the number of votes granted to it in 
accordance with Article FOURTH).

     (11) The term "Fair Market Value" means: (i) in case of capital stock, the 
highest closing sale price during the 30-day period immediately preceding the 
date in question of a share of such stock on the Composite Tape for the New York
Stock Exchange Listed Stocks, or, if such stock is not quoted on the Composite 
Tape, on the New York Stock Exchange, or if such stock is not listed on such
Exchange, on the principal United States securities exchange registered under
the Exchange Act on which such stock is listed, or, if such stock is not listed
on any such stock exchange, the highest closing bid quotation with respect to a
share of such stock during the 30-day period preceding the date in question on
the National Association of Securities Dealers, Inc. Automated Quotations System
or any successor system then in use, or if no such quotations are available, the
fair market value on the date in question of a share of such stock as determined
in good faith by the Board of Directors without counting the vote of any
director who is not a Disinterested Director; and (ii) in the case of

                                       7

<PAGE>
 
     property other than cash or stock, the fair market value of such property
     on the date in question as determined in good faith by the Board of
     Directors without counting the vote of any director who is not a
     Disinterested Director.

          (12) A Related Person shall be deemed to have acquired a share of the
     Voting Stock of the Corporation at the time when such Related Person became
     the beneficial owner thereof. If the Board of Directors without counting
     the vote of any director who is not a Disinterested Director is not able to
     determine the price at which a Related Person has acquired a share of
     Voting Stock of the Corporation, such price shall be deemed to be the Fair
     Market Value of the shares in question at the time when the Related Person
     becomes the beneficial owner thereof. With respect to shares owned by
     Affiliates or other persons whose ownership is attributed to a Related
     Person under the foregoing definition of Related Person, the price deemed
     to be paid therefor by such Related Person shall be the price paid upon the
     acquisition thereof by such Affiliate, Associate or other person, or, if
     such price is not determined by the Board of Directors without counting the
     vote of any director who is not a Disinterested Director, the Fair Market
     Value of the shares in question at the time when the Affiliate, Associate,
     or other such person became the beneficial owner thereof.

     III. The fact that any Business Combination complies with the provisions of
paragraph I(2) of this Article TWELFTH shall not be construed to impose any 
fiduciary duty, obligation or responsibility on the Board of Directors, or any 
member thereof, to approve such Business Combination or recommend its adoption 
or approval to the stockholders of the Corporation, nor shall such compliance 
limit, prohibit or otherwise restrict in any manner the Board of Directors, or 
any member thereof, with respect to evaluations of or actions and responses 
taken with respect to such Business Combination.

     IV. The Board of Directors of the Corporation shall have the power and 
duty to determine for the purposes of this Article TWELFTH, on the basis of 
information known to them after reasonable inquiry and in accordance with the 
terms of this Article TWELFTH, whether a person is a Related Person and whether 
a director is a Disinterested Director. Once the Board of Directors has made a 
determination pursuant to the preceding sentence that a person is a Related 
Person, the Board of Directors of the Corporation, without counting the vote of 
any director who is not a Disinterested Director, with respect to such Related 
Person, shall have the power and duty to interpret all of the terms and 
provisions of this Article TWELFTH and to determine on the basis of the 
information known to them after reasonable inquiry all facts necessary to 
ascertain compliance

                                       8

<PAGE>
 
with this Article TWELFTH including, without limitation, (1) the number of
shares of Voting Stock beneficially owned by any person, (2) whether a person is
an Affiliate or Associate of another, (3) the Fair Market Value of assets,
property, securities or other consideration, and (4) whether all of the
applicable conditions set forth in paragraph I(2) of this Article TWELFTH have
been met with respect to any Business Combination. All actions required or
permitted to be taken pursuant to this Article TWELFTH by the Board of Directors
of the Corporation without counting the vote of any director who is not a
Disinterested Director shall be taken with or without a meeting by the vote or
written consent of a majority of such Disinterested Director, regardless of
whether the Disinterested Directors constitute a quorum of the members of the
Board of Directors then in office. Any determination pursuant to this Article
TWELFTH made in good faith shall be binding and conclusive on all parties.

     V. Nothing herein shall be construed to relieve any Related Person from any
fiduciary obligation imposed by law.

     VI. Notwithstanding any provisions of this Restated Certificate of 
Incorporation or the By-laws of the Corporation (and notwithstanding the fact
that a lesser percentage may otherwise be specified by law, this Restated
Certificate of Incorporation or the By-laws), the affirmative vote of not less
than seventy-five percent (75%) of the total voting power of all outstanding
Voting Stock shall be required to alter, amend or repeal, or adopt any
provisions inconsistent with, the provisions set forth in this Article TWELFTH,
provided, however, that this Article TWELFTH or any provision hereof may be
altered, amended or repealed, or any inconsistent provision may be adopted, upon
the affirmative vote of the holders of not less than a majority of the total
voting power of all outstanding Voting Stock, if such alteration, amendment or
repeal, or if such adoption of any inconsistent provision, shall first have been
approved and recommended by the Board of Directors without counting the vote of
any director who is not a Disinterested Director."

     SECOND: That thereafter, pursuant to resolution of its Board of Directors, 
an annual meeting of the stockholders of the Corporation was duly called and 
held, upon notice in accordance with Section 222 of the General Corporation Law 
of the State of Delaware, at which meeting the necessary number of shares as 
required by statute were voted in favor of the amendments.

     THIRD: That said amendments were duly adopted in accordance with the
applicable provisions of Section 242 of the General Corporation Law of the State
of Delaware.

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<PAGE>
 
     IN WITNESS WHEREOF, BancTec, Inc. has caused this Certificate to be signed 
by its Senior Vice President, and attested by its Secretary, this 12th day of 
January, 1989.

                                       BANCTEC, INC.



                                       By: /s/ G. Wesley Mayland
                                          --------------------------
                                               G. Wesley Mayland,
                                               Senior Vice President

ATTEST:


    /s/ Tod V. Mongan
----------------------------
  Tod V. Mongan, Secretary

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