EXHIBIT 4.5

                         SUPPLEMENTAL WARRANT AGREEMENT

         This  SUPPLEMENTAL  WARRANT  AGREEMENT  IS EFFECTIVE AS OF December 23,
1997 by and among ELCOTEL,  INC.  ("Elcotel");  TECHNOLOGY  SERVICE GROUP,  INC.
("TSG"); LIBERTY BANK AND TRUST COMPANY OF OKLAHOMA CITY, N.A. ("Liberty");  and
AMERICAN STOCK TRANSFER AND TRUST COMPANY ("American").

         WHEREAS, TSG and Liberty entered into a Warrant Agreement,  dated as of
May 10, 1996 (the  "Warrant  Agreement")  pursuant to which Liberty has acted as
Warrant Agent in connection with the issuance of 1,150,000  warrants to purchase
common stock of TSG (the "Warrants") pursuant to the Warrant Agreement;

         WHEREAS,  Elcotel, TSG and Elcotel Hospitality  Services,  Inc. ("EHS")
entered into an Agreement and Plan of Merger,  dated August 13, 1997, as amended
(the "Merger  Agreement")  pursuant to which EHS, a  wholly-owned  subsidiary of
Elcotel,  merged with and into TSG and TSG became a  wholly-owned  subsidiary of
Elcotel effective on December 18, 1997 (the "Merger"), and pursuant thereto each
share of  common  stock of TSG  ("TSG  Common  Stock")  issued  and  outstanding
immediately prior to the consummation of the Merger was converted into the right
to receive 1.05 shares of common stock of Elcotel ("Elcotel Common Stock);

         WHEREAS,  pursuant to the Merger  Agreement,  each Warrant  outstanding
immediately  prior to the  effective  time of the Merger was  adjusted as of the
effective  time of the  Merger so as to  constitute  a warrant  to  acquire,  on
substantially  the same terms and conditions as were  applicable to such Warrant
under the Warrant Agreement,  1.05 shares of Elcotel Common Stock for each share
of TSG Common Stock for which such Warrant could have been exercised immediately
prior to the effective time of the Merger;

         WHEREAS, Liberty desires to resign as Transfer Agent and Warrant Agent,
and American,  as a stock transfer company doing business in New York, New York,
desires to succeed Liberty as Transfer Agent and Warrant Agent under the Warrant
Agreement.

         NOW, THEREFORE, in consideration of the foregoing,  the parties hereto,
intending to be legally bound hereby, agree as follows:

         1. Liberty hereby resigns its duties pursuant to the Warrant  Agreement
effective as of the date set forth above and Liberty  shall be  discharged  from
all further rights,  duties and liabilities  under the Warrant Agreement (except
liabilities  arising as a result of its gross  negligence or willful  misconduct
under the Warrant Agreement). TSG and Elcotel hereby appoint American as the new
Warrant Agent and Transfer Agent under the Warrant Agreement effective as of the
date set forth above and American  accepts such  appointment  and hereby assumes
all rights and duties of the Transfer  Agent and Warrant Agent under the Warrant
Agreement.  American  shall be vested with the same powers,  rights,  duties and
responsibilities  as if it had been originally named in the Warrant Agreement as
the Transfer Agent and Warrant Agent, without any further assurance, conveyance,
act or deed.

         2. If for any reason it shall be  necessary or expedient to execute and
deliver any further assurance,  conveyance, act or deed, upon TSG's request, the
same shall be done at the expense of TSG and Liberty  shall  legally and validly
execute and deliver the same.


<PAGE>

         3. The  following  addresses  set forth in  paragraph 12 of the Warrant
Agreement  to which  notices  shall be sent is modified  so that  notices to the
Company shall be sent to Technology  Service  Group,  Inc. 6428 Parkland  Drive,
Sarasota,  Florida 34243,  Attention:  President and to the Warrant Agent at its
Corporate Office at 40 Wall Street, New York, New York 10005.

         4. This Agreement may be executed in any number of  counterparts,  each
of which shall be an original,  but such counterparts shall together  constitute
but one instrument.

IN WITNESS WHEREOF,  the parties hereto have executed this Supplemental  Warrant
Agreement as of the date first above written.

TECHNOLOGY SERVICE GROUP, INC.                     ELCOTEL, INC.

By: /s/ William H. Thompson                        By: /s/ Tracey L. Gray
    -----------------------------------                -------------------------
    William H. Thompson, Vice President                Tracey L. Gray, President

LIBERTY BANK AND TRUST COMPANY OF OKLAHOMA CITY, N.A.

By: /s/ Edith Schuler
   -----------------------------
   Name: Edith Schuler
   Title: Assistant Vice President

AMERICAN STOCK TRANSFER AND TRUST COMPANY

By: /s/ Herbert J. Lemmer
   -----------------------------
   Name:  Herbert J. Lemmer
   Title:  Vice President


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