SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 SCHEDULE 13D/A
                                 (Rule 13d-101)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
            TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO
                                  RULE 13d-2(a)

                                (Amendment No. 1)


                    CELLULAR TECHNICAL SERVICES COMPANY, INC.
- --------------------------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, par value $.001 per share
- --------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    151167103
- --------------------------------------------------------------------------------
                                 (CUSIP Number)

                             Edward R. Mandell, Esq.
                      Jenkens & Gilchrist Parker Chapin LLP
                              The Chrysler Building
                              405 Lexington Avenue
                            New York, New York 10174
                                 (212) 704-6000
- --------------------------------------------------------------------------------
           (Name, Address and Telephone Number of Person Authorized to
                      Receive Notices and Communications)

                                  May 27, 2003
- --------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of This Statement)

         If the filing person has  previously  filed a statement on Schedule 13G
to report the  acquisition  which is the subject of this  Schedule  13D,  and is
filing this schedule because of Rule 13d-1(e),  13d-1(f) or 13d-1(g),  check the
following box. [ ]

                  Note:  Schedules  filed in paper format shall include a signed
         original and five copies of the schedule,  including all exhibits.  See
         Rule 13d-7(b) for other parties to whom copies are to be sent.


                         (Continued on following pages)





CUSIP No. 151167103                                                  Page 2 of 5


    1       NAME OF REPORTING PERSON
            S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

            Stephen Katz
            --------------------------------------------------------------------

    2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*            (a) [ ]
                                                                         (b) [ ]


    3       SEC USE ONLY

            --------------------------------------------------------------------

    4       SOURCE OF FUNDS*

            PF
            --------------------------------------------------------------------

    5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
            TO ITEMS 2(d) or 2(e)                                            [ ]


    6       CITIZENSHIP OR PLACE OF ORGANIZATION

            United States of America
            --------------------------------------------------------------------

                        7  SOLE VOTING POWER    174,120 (includes currently
      NUMBER OF                                 exercisable options to purchase
        SHARES                                  43,290 shares of common stock
     BENEFICIALLY                               and 41,273 shares of common
       OWNED BY                                 stock held by a partnership that
         EACH                                   is controlled by Mr. Katz
      REPORTING                                 --------------------------------
        PERSON
         WITH           8  SHARED VOTING POWER      0
                                                --------------------------------

                        9  SOLE DISPOSITIVE POWER  174,120 (includes currently
                                                   exercisable options to
                                                   purchase 43,290 shares of
                                                   common stock and 41,273
                                                   shares of common stock held
                                                   by a partnership that is
                                                   controlled by Mr. Katz)
                                                  ------------------------------

                       10  SHARED DISPOSITIVE POWER   0
                                                   -----------------------------


11          AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

            174,120 (includes currently exercisable options to purchase 43,290
                    shares of common stock and 41,273 shares of common stock
                    held by a partnership that is controlled by Mr. Katz)
            --------------------------------------------------------------------

12          CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
            SHARES*                                                         [ ]


13          PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

            7.46%
            --------------------------------------------------------------------

14          TYPE OF REPORTING PERSON*

            IN
            --------------------------------------------------------------------
                      *SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 151167103                                                  Page 3 of 5



Item 1.             Security and Issuer.

         This statement  relates to the common stock,  par value $.001 per share
(the "Common Stock"),  of Cellular Technical Services Company,  Inc., a Delaware
corporation (the "Company").  The address of the Company's  principal  executive
offices is 2815 Second Avenue, Suite 100, Seattle, Washington 98121.

Item 2.             Identity and Background.

         (a) The name of the individual filing this statement is Stephen Katz.

         (b) Mr.  Katz's  business  address is c/o Cellular  Technical  Services
Company, Inc., 20 East Sunrise Highway, Valley Stream, NY 11581.

         (c) Mr. Katz's  principal  occupations are Chairman and Chief Executive
Officer of the Company and engaging in personal investments.

         (d) Mr. Katz has not,  during the last five years,  been convicted in a
criminal proceeding (excluding traffic violations or similar misdemeanors).

         (e) Mr.  Katz has not,  during the last five  years,  been a party to a
civil proceeding of a judicial or administrative body of competent  jurisdiction
as a result of which he was or is subject to a  judgment,  decree or final order
enjoining future violations of, or prohibiting or mandating  activities  subject
to federal or state  securities  laws or finding any  violation  with respect to
such laws.

         (f) Mr. Katz is a citizen of the United States of America.


Item 3.  Source and Amount of Funds or Other Consideration.

         Only  personal  funds were used by Mr. Katz to  purchase  the shares of
Common Stock.


Item 4.  Purpose of Transaction.

         Mr. Katz  purchased  the Common  Stock for  investment  purposes  only.
Unless  otherwise set forth herein,  and excepting the activities of Mr. Katz on
behalf of the Company in his official capacities as an officer and director, Mr.
Katz has no plans or  proposals  which  relate to or would  result  in:  (a) the
acquisition or disposition by any person of additional securities of the Company
or  disposition  of securities of the Company,  (b) an  extraordinary  corporate
transaction,  such as a merger,  reorganization  or  liquidation  involving  the
Company, (c) a sale or transfer of a material amount of assets of the Company or
any of its  subsidiaries,  (d) any change in the present  board of  directors or
management of the Company, including any plans or proposals to change the number
or term of  directors or to fill any  existing  vacancies on the board,  (e) any
material change in the present capitalization or dividend policy of the Company,
(f) any other material change in the Company's business or corporate  structure,
(g) any change in the Company's  charter,  by-laws or instruments  corresponding
thereto or other  actions  which may impede  the  acquisition  of control of the
Company by any person,  (h) a class of  securities of the Company to be delisted
from a national securities exchange or cease being authorized to be quoted in an
inter-dealer  quotation system of a registered national securities  association,
(i)  a  class  of  equity  securities  of  the  Company  becoming  eligible  for
termination  of  registration  pursuant to Section  12(g)(4)  of the  Securities
Exchange Act of 1934 or (j) any action similar to any of those enumerated above;
except  that Mr.  Katz may from time to time  acquire  additional  shares of the
Company's common stock in the open market.





CUSIP No. 151167103                                                  Page 4 of 5


Item 5.  Interest in Securities of the Issuer.

         (a)  Amount  beneficially  owned:   174,120  shares  of  Common  Stock,
comprising 7.46% of the outstanding shares of Common Stock. This amount includes
currently  exercisable  options to purchase  43,290  shares of common  stock and
41,273  shares of common stock held by a  partnership  that is controlled by Mr.
Katz.

         (b) Mr.  Katz has the sole  power to vote and  dispose  of the  174,120
shares of Common Stock beneficially owned.

         (c) Between April 17 and May 29, 2003, Mr. Katz purchased the number of
shares  of Common  Stock  indicated  in the  table  below  through  open  market
purchases effected through a broker:

                                   Number of Shares of
                                   Common Stock
           Date                    Purchased              Price per Share
           4/3/03                  2,000                     $.70
           4/17/03                 4,000                     $.74
           4/17/03                 4,000                     $.75
           4/17/03                 3,800                     $.76
           4/17/03                   200                     $.80
           4/22/03                   280                     $.75
           4/22/03                 7,670                     $.80
           5/27/03                10,000                     $.60
           5/29/03                   200                     $.60


         On May 28, 2003, Mr. Katz transferred  22,274 shares of Common Stock to
his  spouse  pursuant  to a  financial  settlement  agreement  entered  into  in
connection with divorce proceedings.

         (d) None.

         (e) Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with respect to
        Securities of the Issuer.

         None.

Item 7. Material to be Filed as Exhibits.

         None.





CUSIP No. 151167103                                                  Page 5 of 5

                                    SIGNATURE

         After reasonable  inquiry and to the best of my knowledge and belief, I
certify that the information  set forth in this statement is true,  complete and
correct.


                                                     June 2, 2003
                                          --------------------------------------
                                                       (Date)

                                                /s/ Stephen Katz
                                          --------------------------------------
                                                     (Signature)


                                                    Stephen Katz
                                          --------------------------------------
                                                    (Name/Title)