ComVest Capital Management LLC
                                830 Third Avenue
                            New York, New York 10022

                                                               December 30, 1999





US Wireless Data, Inc.
2200 Powell Street
Emeryville, CA  94603
Attn:  Dean Leavitt


                  Re:      Commitment Letter

Gentlemen:

     Please  be  advised  that in  connection  with the term  sheet  (the  "Term
Sheet"),  dated December 23, 1999 by and between  Commonwealth  Associates  L.P.
("Commonwealth")  and US Wireless Data, Inc. (the  "Company"),  we hereby agree,
subject to the terms and  conditions  as  hereinafter  provided or otherwise set
forth in the Term Sheet to make available to the Company a loan (the "Loan"), in
the  aggregate  principal  amount  of up to  One  Million  Dollars  ($1,000,000)
dollars.

     The Loan will be made in separate tranches (each a "Tranche"), within three
(3) business days of receipt by us in  accordance  with this Letter of a request
for the funding of a Tranche (a "Request Letter") from the Company. Each Request
Letter shall set forth the exact  amount of funds  requested to be loaned in the
particular Tranche and the intended use of the loan proceeds from such Tranche.

     Prior to and as a condition  precedent to funding each  requested  Tranche,
the  Company  shall  provide  to us  (i) a  note  (the  "Note")  executed  by an
authorized officer of the Company evidencing the principal amount of funds to be
provided in the Tranche (in  substantially the form of the initial $195,000 Note
attached  hereto  as  Exhibit  A);  (ii) a  security  agreement  (the  "Security
Agreement") and related  documents  securing the loan evidenced by the Note (the
"Security  Documents"),  executed  by  an  authorized  officer  of  the  Company
(substantially  in the  form of the  Security  Agreement  securing  the  initial
$195,000 Note annexed hereto as Exhibit B); and (iii) evidence  satisfactory  to
us that Dean Leavitt has advanced funds to the Company in a Proportionate Amount



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US Wireless Data, Inc.
         December 30, 1999
         Page 2




to the amount requested in the Request Letter. "Proportionate Amount" shall mean
the product obtained when the amount of the requested Tranche is multiplied by a
fraction, the numerator of which is 100 and the denominator of which is 805.

     Notwithstanding  anything to the contrary provided herein or elsewhere,  we
shall have no  obligation  to fund a Tranche if at the time a Request  Letter is
received  by us and prior to when the funds  requested  in the Tranche are sent,
one or more of the following events shall have occurred:

     1. Dean Leavitt is no longer the President,  Chief Executive  Officer and a
Director of the Company or is unable to effectively act in the capacity required
to perform the required functions of such positions; or

     2.  The   commencement  by  or  against  the  Company  of  any  bankruptcy,
reorganization,   debt  arrangement  or  other  case  or  proceeding  under  any
bankruptcy or insolvency  law, the  appointment of a trustee,  receiver or other
custodian for the Company or any of its assets, the making of any assignment for
the  benefit  of  creditors  or the  taking  of any  corporate  or other  action
authorizing or initiating any of the foregoing; or

     3. The  Company  shall  have been  unable  to enter  into an  agreement  to
convert,  modify or  purchase  the  Company's  Series B  Preferred  Stock and 6%
Convertible  Debentures  on terms and  conditions  acceptable  to us in our sole
discretion.

     Notwithstanding  anything to the contrary provided herein or elsewhere,  we
may in our sole  discretion  permit a person other than us, which person must be
reasonably  acceptable  to the  Company,  to fund a  portion  of the Loan to the
Company  requested  pursuant to a Request  Letter for all or a portion of one or
more Tranches on the terms and conditions provided herein, and the Company shall
provide to any such person an executed Note  evidencing the principal  amount of
funds provided in such Tranche and the requested  Security  Documents,  provided
that such  documents may be modified as  appropriate  to reflect prior  security
interests of prior  Tranches.  The Company agrees that any employee,  partner or
shareholder of Commonwealth  or any of its affiliates are reasonably  acceptable
for purposes of this Commitment Letter.

     This  Agreement  shall be governed by and construed in accordance  with the
internal  laws of the State of New York without  regard to the conflicts of laws
principles thereof.  The parties hereto hereby agree that any suit or proceeding
arising directly and/or  indirectly  pursuant to or under this instrument or the
consummation of the transactions contemplated hereby, shall be brought solely in
a federal or state court  located in the City,  County and State of New York. By
its execution hereof,  the parties hereby covenant and irrevocably submit to the
in personam  jurisdiction  of the federal and state courts  located in the City,
County and State of New York and agree that any  process in any such  action may
be served upon any of them  personally,  or by certified mail or registered mail
upon them or their agent, return receipt requested, with the same full force and
effect as if personally  served upon them in New York City.  The parties  hereto
waive any claim that any such  jurisdiction  is not a  convenient  forum for any
such suit or proceeding and any defense or lack of in personam jurisdiction with
respect  thereto.  In the  event of any such  action  or  proceeding,  the party
prevailing  therein  shall be entitled to payment from the other party hereto of
its  reasonable   counsel  fees  and   disbursements  in  an  amount  judicially
determined.



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US Wireless Data, Inc.
         December 30, 1999
         Page 3



     Any notice, consent,  request, or other communication given hereunder shall
be deemed  sufficient if in writing and sent by  registered  or certified  mail,
return receipt  requested  addressed to the Company,  at its principal office as
first provided above, Attention: Dean Leavitt and to Commonwealth at its address
provided  above  (or  to  such  other  address  as  either  the  Company  and/or
Commonwealth  shall  provide in writing to the other  party).  Notices  shall be
deemed to have been given on the date of receipt by the other party.

                                      Very truly yours,

                                      ComVest Capital Management LLC



                                      By:
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                                      Name:
                                           -----------------------------------
                                      Title:
                                             ---------------------------------


Accepted and agreed as of the
date first appearing above

US WIRELESS DATA, INC.



By:
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Name:
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Title:
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