<PAGE>

                                                                    EXHIBIT 10.3


     THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 NOR
     UNDER APPLICABLE STATE SECURITIES LAWS AND MAY NOT BE SOLD, TRANSFERRED OR
     OTHERWISE DISPOSED OF UNLESS IT HAS BEEN REGISTERED UNDER SUCH LAWS OR AN
     EXEMPTION FROM REGISTRATION IS AVAILABLE.


                                                              September 25, 2000


                                 BANCTEC, INC.

                          Stock Subscription Warrant
                          --------------------------


Warrant to Subscribe
for 750,000 shares

                         Void after September 25, 2008
                         -----------------------------


     THIS CERTIFIES that, for value received, each of the parties set forth on
Schedule I hereto (each, a "Warrantholder") or its registered assigns, is
entitled, subject to the terms of Section 1 hereof, to subscribe for and
purchase from BancTec, Inc., a Delaware corporation (the "Company"), at the
price of $.01 per share (the "Warrant Price"), at any time prior to September
25, 2008, the number of fully paid, nonassessable shares of Common Stock, par
value $.01 per share, of the Company ("Common Stock"), not to exceed the amount
set forth opposite each Warrantholder's name on Schedule I hereto, subject,
however, to the provisions and upon the terms and conditions hereinafter set
forth, including, without limitation, the provisions of Section 3 hereof.

     Section 1.  Exercise of Warrant.  Any Warrantholder may exercise its
Warrant, in whole or in part (but not as to a fractional share of Common Stock),
by the completion of the subscription form attached hereto and by the surrender
of this Warrant (properly endorsed) at the principal executive offices of the
Company (or at such other agency or office of the Company in the United States
as it may designate by notice in writing to the Warrantholders at their address
appearing on the books of the Company), and by payment to the Company of the
Warrant Price, at the election of such holder, (i) in cash or by certified or
official bank check, for each share being purchased, or (ii) by receiving from
the Company the number of shares of Common Stock equal to the number of shares
of Common Stock otherwise issuable upon such exercise less the number of shares
of Common Stock having a fair market value on the date of exercise equal to the
Warrant Price applicable to the number of shares of Common Stock for which this
Warrant is being exercised.

                                       1
<PAGE>

     (a) In the event of any exercise of the rights represented by this Warrant,
a certificate or certificates for the shares of Common Stock so purchased,
registered in the name of the exercising Warrantholder, shall be delivered to
such holder within a reasonable time, not exceeding three business days, after
the rights represented by this Warrant shall have been so exercised; and, unless
this Warrant has expired or been exercised in full, a new Warrant representing
the number of shares (except a remaining fractional share), if any, with respect
to which this Warrant shall not then have been exercised shall also be issued to
the Warrantholders within such time. With respect to any such exercise, the
exercising Warrantholder shall for all purposes be deemed to have become the
holder of record of the number of shares of Common Stock evidenced by such
certificate or certificates from the date on which this Warrant was surrendered
and payment of the Warrant Price was made irrespective of the date of delivery
of such certificate, except that, if the date of such surrender and payment is a
date on which the stock transfer books of the Company are closed, such person
shall be deemed to have become the holder of such shares at the close of
business on the next succeeding date on which the stock transfer books are open.
No fractional shares shall be issued upon exercise of this Warrant. If any
fractional interest in a share of Common Stock would, except for the provisions
of this Section 1, be delivered upon any such exercise, the Company, in lieu of
delivering the fractional share thereof, shall pay to the exercising
Warrantholder an amount in cash equal to the current fair market value of such
fractional interest.

     (b) For purposes hereof, the fair market value of a share of Common Stock
on any date shall be equal to (A) the fair market value of the Company's Common
Stock determined on the basis of (1) the last sale price of shares of Common
Stock, regular way, on such date or, if no such sale takes place on such date,
the average of the closing bid and asked prices thereof on such date, in each
case as officially reported on the principal national securities exchange on
which the Common Stock is then listed or admitted to trading, or (2) if no
shares of Common Stock are then listed or admitted to trading on any national
securities exchange but the Common Stock is designated as a national market
system security by the National Association of Securities Dealers, the last
trading price of the Common Stock on such date, or (B) if shares of Common Stock
are not then listed or admitted to trading on any national exchange or
designated as a national market system security, the fair market value thereof
as determined by the Board of Directors of the Company in good faith.

     Section 2.  Adjustment of Warrant Price and Number of Shares.

     (a) Subdivision or Combination of Stock.  In case the Company shall at
any time subdivide its outstanding shares of Common Stock into a greater number
of shares, the Warrant Price in effect immediately prior to such subdivision
shall be proportionately reduced, i.e., the Warrantholders shall be entitled to
purchase after such subdivision, for the same consideration as applicable prior
to such subdivision, the same percentage of outstanding Common Stock that such
holders were entitled to purchase prior to such subdivision, and conversely, in
case the outstanding shares of Common Stock of the Company shall be combined
into a smaller number of shares, the Warrant Price in effect immediately prior
to such combination shall be proportionately increased.

                                       2
<PAGE>

     (b) Reorganization, Reclassification, Consolidation, Merger or Sale. If any
capital reorganization or reclassification of the capital stock of the Company
or any consolidation or merger of the Company with another corporation, or the
sale of all or substantially all its assets to another corporation shall be
effected in such a way that holders of Common Stock shall be entitled to receive
stock, securities or assets with respect to or in exchange for Common Stock,
then, as a condition of such reorganization, reclassification, consolidation,
merger or sale, lawful and adequate provisions shall be made whereby each
Warrantholder shall thereafter have the right to receive upon the basis and upon
the terms and conditions specified herein and in lieu of the shares of Common
Stock of the Company immediately theretofore receivable upon the exercise of
such Warrantholder's Warrants, such shares of stock, securities or assets
(including cash) as may be issued or payable with respect to or in exchange for
a number of outstanding shares of Common Stock equal to the number of shares of
such stock immediately theretofore so receivable had such reorganization,
reclassification, consolidation, merger or sale not taken place, and in any such
case this Warrant shall become immediately exercisable, notwithstanding any
other provision contained herein, and appropriate provision shall be made with
respect to the rights and interests of such holder to the end that the
provisions hereof (including, without limitation, provisions for adjustments of
the Warrant Price) shall thereafter be applicable, as nearly as may be, in
relation to any shares of stock, securities or assets thereafter deliverable
upon the exercise of such Warrants (including an immediate adjustment, by reason
of such consolidation or merger, of the Warrant Price to the value for the
Common Stock reflected by the terms of such consolidation or merger if the value
so reflected is less than the Warrant Price in effect immediately prior to such
consolidation or merger). In the event of a merger or consolidation of the
Company as a result of which a greater or lesser number of shares of common
stock of the surviving corporation are issuable to holders of Common Stock of
the Company outstanding immediately prior to such merger or consolidation, the
Warrant Price in effect immediately prior to such merger or consolidation shall
be adjusted in the same manner as though there were a subdivision or combination
of the outstanding shares of Common Stock of the Company. The Company will not
effect any such consolidation, merger or sale, unless prior to the consummation
thereof the successor corporation (if other than the Company) resulting from
such consolidation or merger or the corporation purchasing such assets shall
assume, by written instrument executed and mailed or delivered to each
Warrantholder at the last address of such holder appearing on the books of the
Company, the obligation to deliver to such holder such shares of stock,
securities or assets as, in accordance with the foregoing provisions, such
holder may be entitled to receive upon exercise of such Warrants.

     (c) Notice of Adjustment. Upon any adjustment of the Warrant Price, then
and in each such case the Company shall give written notice thereof, by first
class mail, postage prepaid, addressed to each Warrantholder at the address of
such holder as shown on the books of the Company, which notice shall state the
Warrant Price resulting from such adjustment, setting forth in reasonable detail
the method of calculation and the facts upon which such calculation is based.

                                       3
<PAGE>

     (d) Stock to Be Reserved. The Company shall at all times reserve and keep
available out of its authorized Common Stock or its treasury shares, solely for
the purpose of issuance upon the exercise of this Warrant as herein provided,
such number of shares of Common Stock as shall then be issuable upon the
exercise of this Warrant. The Company covenants that all shares of Common Stock
which shall be so issued shall be duly and validly issued and fully paid and
nonassessable and free from all taxes, liens and charges with respect to the
issue thereof, and, without limiting the generality of the foregoing, the
Company covenants that it will from time to time take all such action as may be
requisite to assure that, in the event that the Company designates a par value
per share of Common Stock, the par value per share of the Common Stock shall be
at all times equal to or less than the effective Warrant Price. The Company
shall take all such action as may be necessary to assure that all such shares of
Common Stock may be so issued without violation of any applicable law or
regulation, or of any requirements of any national securities exchange upon
which the Common Stock of the Company may be listed. The Company shall not take
any action which results in any adjustment of the Warrant Price if the total
number of shares of Common Stock issued and issuable after such action upon
exercise of this Warrant would exceed the total number of shares of Common Stock
then authorized by the Company's Articles of Incorporation. The Company has not
granted and will not grant any right of first refusal with respect to shares
issuable upon exercise of this Warrant, and there are no preemptive rights
associated with such shares.

     (e) Issue Tax. The issuance of certificates for shares of Common Stock upon
exercise of this Warrant shall be made without charge to the exercising
Warrantholder for any issuance tax in respect thereof, provided that the Company
shall not be required to pay any tax which may be payable in respect of any
transfer involved in the issuance and delivery of any certificate in a name
other than that of such holder.

     (f) Closing of Transfer Books. The Company will at no time close its
transfer books against the transfer of the shares of Common Stock issued or
issuable upon the exercise of this Warrant in any manner which interferes with
the timely exercise of this Warrant.

     (g) Definition of Common Stock. As used herein the term "Common Stock"
shall mean and include the Common Stock, $.01 par value, of the Company as
authorized on date hereof, or shares of any class or classes resulting from any
reclassification or reclassifications thereof and in case at any time there
shall be more than one such resulting class, the shares of each class then so
issuable shall be substantially in the proportion which the total number of
shares of such class resulting from all such reclassifications bears to the
total number of shares of all such classes resulting from all such
reclassifications.

     Section 3.  Notices of Record Dates.  In the event of

          (1) any taking by the Company of a record of the holders of any class
     of securities for the purpose of determining the holders thereof who are
     entitled to receive

                                       4
<PAGE>

     any dividend or other distribution (other than cash dividends out of earned
     surplus), or any right to subscribe for, purchase or otherwise acquire any
     shares of stock of any class or any other securities or property, or to
     receive any right to sell shares of stock of any class or any other right;
     or

          (2) any capital reorganization of the Company, any reclassification or
     recapitalization of the capital stock of the Company or any transfer of all
     or substantially all the assets of the Company to or consolidation or
     merger of the Company with or into any other corporation or entity; or

          (3) any voluntary or involuntary dissolution, liquidation or winding-
     up of the Company;

then and in each such event the Company shall give notice to the Warrantholders
specifying (i) the date on which any such record is to be taken for the purpose
of such dividend, distribution or right and stating the amount and character of
such dividend, distribution or right, and (ii) the date on which any such
reorganization, reclassification, recapitalization, transfer, consolidation,
merger, dissolution, liquidation or winding-up is to take place, and the time,
if any is to be fixed, as of which the holders of record of Common Stock will be
entitled to exchange their shares of Common Stock for securities or other
property deliverable upon such reorganization, reclassification,
recapitalization, transfer, consolidation, merger, dissolution, liquidation or
winding-up.  Such notice shall be given at least 20 days and not more than 90
days prior to the date therein specified, and such notice shall state that the
action in question or the record date is subject to (x) the effectiveness of a
registration statement under the Securities Act of 1933, as amended, and
applicable state securities laws, or (y) a favorable vote of stockholders, if
either is required.

     Section 4.  No Stockholder Rights or Liabilities.

     (a)  This warrant shall not entitle the Warrantholders to any voting rights
or other rights as a shareholder of the Company. No provision hereof, in the
absence of affirmative action by any the Warrantholder to purchase shares of
Common Stock, and no mere enumeration herein of the rights or privileges of any
Warrantholder, shall give rise to any liability of such holder for the Warrant
Price or as a stockholder of the Company, whether such liability is asserted by
the Company or by creditors of the Company.

     (b) If the Company, at any time while this Warrant is outstanding, shall
make a distribution to the holders of its Common Stock of its property or assets
as a dividend in liquidation or partial liquidation or by way of return of
capital or any dividend payable out of funds legally available for dividends
under the laws of the State of Delaware each Warrantholder shall be entitled to
receive at the time of such distribution, without payment of any consideration,
a sum equal to the amount of such property or assets as would have been payable
to such holder as an owner of the shares issuable upon the exercise hereof had
such holder been the holder of record of such shares on the record date for such
distribution; and an appropriate provision with respect to such payment to such
holder as described in this paragraph (b) shall be made a part of any such
distribution.

                                       5
<PAGE>

     Section 5.  Lost, Stolen, Mutilated or Destroyed Warrant. If this Warrant
is lost, stolen, mutilated or destroyed, the Company may, on such terms as to
indemnity or otherwise as it may in its discretion reasonably impose (which
shall, in the case of a mutilated Warrant, include the surrender thereof), issue
a new Warrant of like denomination and tenor as the Warrant so lost, stolen,
mutilated or destroyed. Any such new Warrant shall constitute an original
contractual obligation of the Company, whether or not the allegedly lost,
stolen, mutilated or destroyed Warrant shall be at any time enforceable by
anyone.

     Section 6.  Notices.  All notices, requests and other communications
required or permitted to be given or delivered hereunder shall be in writing,
and shall be delivered, or shall be sent by national overnight courier service
or by certified or registered mail, postage prepaid, or sent by fax, and
addressed, if to any Warrantholder, to such holder at the address or fax shown
on the records of the Company or at such other address or fax number as shall
have been furnished to the Company by notice from such holder and, if to the
Company, addressed to the Company at 2701 East Grauwyler Road, Irving, Texas
75061, fax: (972) 579-6448; Attn: President, or at such other address or fax
number as shall have been furnished to the Warrantholders by notice from the
Company.


     IN WITNESS WHEREOF, BancTec, Inc., has executed this Warrant on and as of
the day and year first above written.


                                         BANCTEC, INC.


                                         By: /s/ Richard A. McDonough
                                             -------------------------
                                             Name:  Richard A. McDonough
                                             Title:  Secretary

                                       6
<PAGE>

                                  SCHEDULE I


<TABLE>
<CAPTION>
                                                                              Number of Shares
Name and Address of Warrantholder                                              of Common Stock
---------------------------------                                             -----------------
<S>                                                                           <C>
Welsh, Carson, Anderson & Stowe VIII, L.P.                                         735,600
WCAS Information Partners, L.P.                                                      1,050
Patrick J. Welsh                                                                     2,340
Russell L. Carson                                                                    2,340
Bruce K. Anderson                                                                    2,340
Andrew M. Paul                                                                       1,780
Thomas E. McInerney                                                                  2,340
Robert A. Minicucci                                                                  1,050
Anthony J. de Nicola                                                                   260
Paul B. Queally                                                                        210
Lawrence B. Sorrel                                                                     210
Rudolph E. Rupert                                                                      160
D. Scott Mackesy                                                                       100
Priscilla A. Newman                                                                     70
Laura M. VanBuren                                                                       30
Sean Traynor                                                                            30
John Almeida                                                                            40
Jonathan Rather                                                                         50
---------------------------------                                             -----------------

Total                                                                              750,000

c/o Welsh, Carson, Anderson & Stowe
320 Park Avenue, Suite 2500
New York, New York 10022
Telecopy: (212) 893-9563
Attention: Robert A. Minicucci
</TABLE>
<PAGE>

                       SUBSCRIPTION FORM TO BE EXECUTED
                         UPON EXERCISE OF THE WARRANT


                                                        Date
                                                             ------------------


To BancTec, Inc.


     The undersigned, pursuant to the provisions set forth in the within
Warrant, hereby agrees to subscribe for and purchase         shares of Common
Stock covered by such Warrant, and herewith tenders $     in full payment of
the purchase price for such shares.


                                       Name of Holder:


                                       By
                                          ------------------------------

                                    Address
                                            -----------------------------
                                            -----------------------------
                                            -----------------------------
                                            -----------------------------