WAIVER OF RIGHTS
                                       AND
                     FIRST AMENDMENT TO DEBENTURE AGREEMENT

     This Waiver of Rights and First Amendment to Debenture Agreement is entered
into  effective as of the 30th day of April 1999,  between U.S.  Wireless  Data,
Inc., a Colorado  corporation  (the "Company") and the undersigned  holders (the
"Holders") of the  Company's 6%  Convertible  Debentures  Due July 21, 2000 (the
"Debentures")  to waive  certain  rights  held by the  Debenture  holders and to
modify and amend the Debenture Agreement relating to the Debentures. RECITALS

          WHEREAS,  the  Company has issued  Debentures  in the  aggregate  face
     amount of $2,000,000;

          WHEREAS,  the  Holders  hold  Debentures  in the face amount set forth
     below its name on the execution page of this Agreement;

          WHEREAS,  the Company owes the undersigned accrued but unpaid interest
     and damages on the  Debentures  through  April 26,  1999 (the  "Calculation
     Date") and has also  agreed to prepay the  balance  of  interest  that will
     become  payable  through June 30, 1999, in the  aggregate  amount set forth
     below each Holder's name on the execution page of this Agreement;

          WHEREAS,  each of the Holders is willing to waive all defaults related
     to the  Debentures  up to the date of this  Agreement,  if the Company pays
     such accrued but unpaid interest and penalties in the form of the Company's
     Series B Cumulative Convertible Redeemable Preferred Stock;

          WHEREAS,  Section III of the Debenture Agreement gives the Holders the
     right to declare the principal and all accrued  interest on such  Debenture
     to be  immediately  due  and  payable  upon  the  satisfaction  of  certain
     conditions;

          WHEREAS,  Section IV.D. of the Debenture  Agreement  gives the Holders
     the  right to  require  the  Company  to  redeem  the  Debentures  upon the
     satisfaction of certain conditions and to receive additional  consideration
     in the event the shares of stock  underlying  the  Debenture are not timely
     registered;

          WHEREAS, the Holders are willing to restrict such rights under Section
     III and Section IV.D. of the Debenture  Agreement in  consideration  of the
     Company  attempting to raise additional capital by selling the Company's 6%
     Series B Cumulative Convertible Redeemable Preferred Stock.

          NOW,  THEREFORE,  in consideration of the Company's  attempts to raise
     additional  capital,   the  opportunity  being  given  to  the  Holders  to
     participate in such offering, and other valuable consideration, the parties
     agrees as follows:

                                                                     Page 1 of 4

     1. The Holders  agree to  exchange  all  accrued  and unpaid  interest  and
damages due on the  Debentures and all interest that will become payable on such
Debentures on or before June 30, 1999 (such aggregate amount set forth below the
undersigned's  name on the execution  page of this  Agreement) for the Company's
Series B Cumulative Convertible Redeemable Preferred Stock, and to waive any and
all previously  occurring or currently  existing  defaults under the Debentures,
the  Debenture  Agreement,  or any related  registration  rights  agreement.  To
accomplish  the  purchase  of the  Company's  Series  B  Cumulative  Convertible
Redeemable  Preferred  Stock,  the  undersigned  agrees to execute a  Securities
Purchase  Agreement in  substantially  the same form as the  agreement  attached
hereto as Exhibit A.

     2.  Notwithstanding  anything to the contrary in any other  agreement,  the
Debenture  Agreement is hereby  amended so that the Holders waive their right to
declare the principal and all accrued interest on the Debentures immediately due
and payable  pursuant to Section III of the  Debenture  Agreement  solely due to
default in the payment of interest  and the failure to register  the  underlying
shares of Common Stock, prior to the date hereof.

     3. The Holders agree not to declare the  principal and accrued  interest on
the  Debentures  due  and  payable  pursuant  to  Section  III of the  Debenture
Agreement  due to any of the  reasons  set forth in  Section 2 above  unless and
until:

          a.  the  holders  of the  Company's  Series B  Cumulative  Convertible
     Redeemable  Preferred  Stock have a then  exercisable  right of  redemption
     regarding  such stock under  Section  2(b)(iv) of the  Registration  Rights
     Agreement annexed to the Securities  Purchase  Agreement attached hereto as
     Exhibit A (the "New Registration Rights Agreement"); or

          b. 180 days have elapsed following the "Closing Date" (as that term is
     defined in the New Registration Rights Agreement).

     4. Notwithstanding anything to the contrary in any other agreement, Section
IV.D of the Debenture Agreement is hereby amended such that:

          a. the Holders  will not have any right to force the Company to redeem
     any  Debenture  unless  and until the  holders  of the  Company's  Series B
     Cumulative  Convertible  Redeemable Preferred Stock have a then exercisable
     right of redemption  regarding such stock under Section 2(b)(iv) of the New
     Registration Rights Agreement; and

          b. the Holders will have no future right to accrue any penalty for the
     Company's failure to file a registration statement regarding the securities
     underlying the Debentures (the "Registration Statement"),  or the Company's
     failure to cause the Registration Statement to become effective, other than
     as set forth below:

               i. If the Registration Statement is not filed in proper form with
          the  Securities  and  Exchange  Commission  on or before the  Required
          Filing  Date (as that term is 

                                                                     Page 2 of 4

          defined in the New Registration  Rights  Agreement),  then the Company
          shall pay the undersigned a late filing penalty on the first day after
          such Required  Filing Date in an amount equal to three percent (3%) of
          the face amount of the Debentures then held by the Holders.

               ii. If the  Registration  Statement  is not filed in proper  form
          with the Securities and Exchange  Commission on or before each monthly
          anniversary  of the  Required  Filing Date (as that term is defined in
          the New Registration Rights Agreement), then the Company shall pay the
          Holders a late filing  penalty on each such date in an amount equal to
          three percent (3%) of the face amount of the  Debentures  then held by
          the Holders.

               iii. If the Registration  Statement is not effective on or before
          the  Required  Effective  Date (as  that  term is  defined  in the New
          Registration Rights Agreement), then the Company shall pay the Holders
          a late filing  penalty on the first day after such Required  Effective
          Date in an amount  equal to three  percent  (3%) of the face amount of
          the Debentures then held by the Holders.

               iv. If the  Registration  Statement is not effective on or before
          each monthly  anniversary of the Required Effective Date (as that term
          is defined in the New Registration Rights Agreement), then the Company
          shall pay the  Holders a late  filing  penalty on each such date in an
          amount equal to two percent (2%) of the face amount of the  Debentures
          then held by the Holders.

     5. Except for the remedies  granted to the Holders  pursuant to Section III
and Section IV of the Debenture Agreement,  the Holders do not waive any and all
other remedies  available to them under the Debenture  Agreement and any related
New Registration Rights Agreement.

     6. In all other  respects the Debenture and the Debenture  Agreement  shall
remain unchanged.

     7. This Waiver and  Amendment  Agreement  shall not be binding on any party
until  similar  agreements  are fully  executed by all Holders and the  Company.
Notwithstanding  the  foregoing,  this  Waiver and  Amendment  Agreement  may be
executed in counterparts and by facsimile signature.

     8. This Waiver and Amendment Agreement shall be construed under the laws of
the State of Colorado for contracts  executed and to be performed  fully in such
State.


     IN WITNESS  WHEREOF,  each of the undersigned have executed this Waiver and
Amendment Agreement effective as of the date first above written.

                                                                     Page 3 of 4


U.S. Wireless Data, Inc.

By:                                               
     --------------------------------------------------

Print Name:                                       
            -------------------------------------------

Title:                                            
      -------------------------------------------------

Date:                                             
     --------------------------------------------------


Debenture Holder                             Debenture Holder

By:                                          By:                            
   -------------------------------------        --------------------------------

Print Name:                                  Print Name:     
           -----------------------------                ------------------------

Title:                                        Title:        
      ----------------------------------            ----------------------------

Date:                                         Date:           
     -----------------------------------           -----------------------------

Face Amount of                                  Face Amount of:
Debentures Held:  $                             Debentures Held:  $
                    --------------------                            ------------
Aggregate Interest and                          Aggregate Interest and
Penalties Owed as of                            Penalties Owed as of
the calculation date: $                         the calculation date: $
                       -----------------                               ---------
                           Debenture Holder

                           By:                    
                               --------------------------------------

                           Print Name:     
                                      -------------------------------

                           Title:             
                                 ------------------------------------

                           Date:             
                                -------------------------------------

                           Face Amount of
                           Debentures Held:  $
                                              -----------------------     
                           Aggregate Interest and
                           Penalties Owed as of
                           the Calculation Date:  $  
                                                   ------------------
                                                                     Page 4 of 4



                                    EXHIBIT A

                      FORM OF SECURITIES PURCHASE AGREEMENT
                   WITH REGISTRATION RIGHTS AGREEMENT ANNEXED
            
             [Filed herewith as Exhibit 4.1 and 4.2, respectively.]