These  Warrants have not been  registered  under the  Securities Act of 1933, as
amended (the  "Act"),  and may not be sold,  transferred,  assigned or otherwise
disposed of unless the person  requesting  the  transfer of the  Warrants  shall
provide an opinion of counsel to Preferred  Voice,  Inc. (the  "Company")  (both
counsel and opinion to be  satisfactory  to the Company) to the effect that such
sale, transfer,  assignment or disposition will not involve any violation of the
registration provisions of the Act or any similar or superseding statute.

No.       100                                             100,000    Warrants
    --------------                                       ----------

                              PREFERRED VOICE, INC.

                               WARRANT CERTIFICATE

     This warrant certificate ("Warrant  Certificate")  certifies that for value
received Invest,  Inc. (the "Initial  Warrant Holder") or registered  assigns is
the owner of the number of warrants  specified above, each of which entitles the
holder  thereof  to  purchase,  at any time on or  before  the  Expiration  Date
hereinafter  provided,  one fully paid and non-assessable share of common Stock,
$0.001 par value per share,  of Preferred  Voice,  Inc., a Delaware  corporation
(the "Company"),  at a purchase price of $1.25 per share of Common Stock payable
in lawful money of the United  States of America,  in cash,  by official bank or
certified check, or by wire transfer ("Warrants").

1.       Warrant; Purchase Price

         Each Warrant shall entitle the holder  thereof to purchase one share of
Common Stock, $0.001 par value per share, of the Company ("Common Stock") during
the period  commencing on the date hereof and ending on the Expiration Date. The
purchase  price payable upon exercise of a Warrant shall be $1.25 (the "Purchase
Price").  The  Purchase  Price and number of Warrants  evidenced by this Warrant
Certificate  are subject to  adjustment  as provided in Article 7. Common  Stock
purchased  or subject  to  purchase  pursuant  to the  Warrants  shall be called
"Warrant Shares" herein.

2.       Exercise; Expiration Date

         2.1 Each Warrant is  exercisable,  at the option of the holder,  at any
time  after  issuance  and on or  before  the  Expiration  Date.  In the case of
exercise of less than all the Warrants represented by a Warrant Certificate, the
Company  shall cancel the Warrant  Certificate  upon the  surrender  thereof and
shall  execute  and deliver a new  Warrant  Certificate  for the balance of such
Warrants.

         2.2 The term  "Expiration  Date"  shall mean 5:00 p.m.  Dallas  time on
November 12, 2000  or if such date shall in the State of Texas be a holiday or a
day on which banks are authorized to close,  then 5:00 p.m. Dallas time the next
following  day which in the  State of Texas is not a  holiday  or a day on which
banks are authorized to close.

<PAGE>

3.       Registration and Transfer on Company Books

         3.1 The Company shall maintain books for the  registration and transfer
of Warrant Certificates.

         3.2 Prior to due  presentment  for  registration  of  transfer  of this
Warrant Certificate, the Company may deem and treat the registered holder as the
absolute owner thereof.

         3.3 The Company shall register upon its books any transfer of a Warrant
Certificate upon surrender of same to the Company accompanied (if so required by
the Company) by a written instrument of transfer duly executed by the registered
holder or by a duly authorized attorney. Upon any such registration of transfer,
new  Warrant  Certificate(s)  shall  be  issued  to the  transferee(s)  and  the
surrendered  Warrant  Certificate  shall be cancelled by the Company.  A Warrant
Certificate may also be exchanged,  at the option of the holder, for new Warrant
Certificates  representing in the aggregate the number of Warrants  evidenced by
the Warrant Certificate surrendered.

4.       Securities Law Registration

         4.1 The Warrant Shares will not be registered  under the Securities Act
or any state securities law and shall not be transferrable  unless registered or
an exemption from  registration is available.  A legend to the foregoing  effect
will be placed on any certificate representing such shares.

         4.2 If, at any time within  five (5) years of the date of this  Warrant
Certificate,  the  Company  proposes  for  any  reason  to  register  any of its
securities  under the  Securities  Act  other  than a  registration  on Form S-8
relating solely to employee stock option or purchase plans, on Form S-4 relating
solely  to an SEC Rule 145  transaction  or on any  other  form  which  does not
include  substantially  the same information as would be required to be included
in a registration  statement  covering the sale of the Warrant Shares,  it shall
each such time  give  written  notice  to the  holder of these  Warrants  or the
Warrant  Shares  ("Holder"  for  purposes  of this  Section 4) of the  Company's
intention to register  such  securities,  and, upon the written  request,  given
within thirty (30) days after receipt of any such notice,  of the Holders of the
Warrants and Warrant Shares outstanding,  to register any of the Warrant Shares,
the  Company  shall cause the Warrant  Shares so  requested  by the Holder to be
registered,  whether such Warrant Shares are  outstanding or subject to purchase
hereby,  to be registered  under the Securities Act, all to the extent requisite
to permit the sale or other  disposition  by the Holder of the Warrant Shares so
registered;  provided, however, that the Warrant Shares as to which registration
had been requested need not be included in such  registration  if in the opinion
of counsel for the Company and counsel for the Holder the  proposed  transfer by
the Holder may be effected without registration under the Securities Act and any
certificate  evidencing the Warrant Shares need not bear any restrictive legend.
In the event that any  registration  pursuant  to this  Section 4.2 shall be, in
whole or in part, an  underwritten  offering of securities of the Company,  then
(i) any request  pursuant to this  Section  4.2 to register  Warrant  Shares may
specify  that such  shares are to be included  in the  underwriting  on the same
terms and  conditions  as the shares of the Company's  capital  stock  otherwise
being sold through underwriters under such

                                                          -2-

<PAGE>

registration,  (ii) if the managing underwriter of such offering determines that
the number of shares to be offered by all selling  shareholders must be reduced,
then the Company shall have the right to reduce the number of shares  registered
on behalf of the Holder,  provided that the number of shares to be registered on
behalf of the Holder  shall not be  reduced to such an extent  that the ratio of
the shares  which the Holder is  permitted  to register  to the total  number of
shares  the  Holder  owns  is  less  than  that  ratio  for  any  other  selling
shareholder, and (iii) the Holder will be bound by the terms of the underwriting
agreement and the conditions imposed by the underwriter on selling shareholders.

         4.3 If and whenever the Company is under an obligation  pursuant to the
provisions  of this  Warrant  Certificate  to register any Warrant  Shares,  the
Company shall, as expeditiously as practicable:

                  (a)  prepare  and  file  with  the   Securities  and  Exchange
         Commission (the "Commission") a registration  statement with respect to
         such  shares  and use its  best  efforts  to  cause  such  registration
         statement to become and remain effective for at least nine (9) months;

                  (b) prepare and file with the Commission  such  amendments and
         supplements to such  registration  statement and the prospectus used in
         connection  therewith  as may be  necessary  to keep such  registration
         statement  effective  for at least nine  months and to comply  with the
         provisions  of the  Securities  Act with  respect  to the sale or other
         disposition  of  all  Warrant  Shares  covered  by  such   registration
         statement;

                  (c)  furnish to the Holder a suitable  number of copies of all
         preliminary and final  prospectuses to enable the Holder to comply with
         the requirements of the Securities Act, and such other documents as the
         Holder may reasonably request in order to facilitate the public sale or
         other disposition of the Warrant Shares;

                  (d) use its best  efforts to  register  or qualify the Warrant
         Shares covered by such registration  statement under such securities or
         blue sky laws of such  jurisdictions  as the  Holder  shall  reasonably
         request  and  where  registration  or  qualification  will not  involve
         unreasonable expense or delay and provided,  however,  that the Company
         will not have to  register  or  qualify  in any  state in which  solely
         because of such  registration or qualification it would have to qualify
         to do business;  and the Company shall do any and all other  reasonable
         acts and  things  which may be  necessary  or  advisable  to enable the
         Holder  to  consummate  the  public  sale or other  disposition  of the
         Warrant Shares in such jurisdiction;

                  (e) notify the Holder, at any time when a prospectus  relating
         to the Warrant Shares is required to be delivered  under the Securities
         Act  within  the  appropriate  period  mentioned  in clause (b) of this
         Section  4.3,  of the  happening  of any event as a result of which the
         prospectus included in such registration  statement, as then in effect,
         includes  an untrue  statement  of a material  fact or omits to state a
         material  fact  required to be stated  therein or necessary to make the
         statements  therein not  misleading  in the light of the  circumstances
         then existing,  and at the request of the Holder prepare and furnish to
         the  Holder a  reasonable  number of copies  of a  supplement  to or an
         amendment of such prospectus as may be necessary so that, as thereafter

                                                          -3-

<PAGE>

         delivered to the  purchasers  of the Warrant  Shares,  such  prospectus
         shall not  include an untrue  statement  of a material  fact or omit to
         state a material  fact  required to be stated  therein or  necessary to
         make  the  statements  therein  not  misleading  in  the  light  of the
         circumstances then existing; and

                  (f) exercise  its best  efforts to furnish,  at the request of
         the Holder on the date that the  Warrant  Shares are  delivered  to the
         underwriters for sale pursuant to such  registration or, if the Warrant
         Shares are not being sold  through  underwriters,  on the date that the
         registration  statements  with  respect  to  such  Warrant  Shares  are
         declared  effective,  (1) an opinion,  dated such date,  of the counsel
         representing  the  Company  for  the  purposes  of  such  registration,
         addressed to the Holder,  stating that such registration  statement has
         become  effective  under the Securities Act and that (i) to the best of
         the  knowledge  of  such  counsel,   no  stop  order   suspending   the
         effectiveness  thereof  has been  issued  and no  proceedings  for that
         purpose have been instituted or are pending or  contemplated  under the
         Securities   Act;  (ii)  the   registration   statement,   the  related
         prospectus, and each amendment or supplement thereto, comply as to form
         in all material  respects with the  requirements  of the Securities Act
         and the applicable  rules and regulations of the Commission  thereunder
         (except  that such  counsel  need  express no  opinion as to  financial
         statements and other financial data contained therein);  and (iii) such
         counsel has no reason to believe that either the registration statement
         or the prospectus, or any amendment or supplement thereto, contains any
         untrue  statement of a material  fact or omits to state a material fact
         required  to be stated  therein  or  necessary  to make the  statements
         therein  not  misleading;  and (2) a letter  dated such date,  from the
         independent  certified public accountants of the Company,  stating that
         they are independent certified public accountants within the meaning of
         the  Securities  Act and the rules and  regulations  of the  Commission
         thereunder and that in the opinion of such  accountants,  the financial
         statements  and other  financial  data of the  Company  included in the
         registration   statement  or  the  prospectus,   or  any  amendment  or
         supplement thereof, comply as to form in all material respects with the
         applicable accounting  requirements of the Securities Act and the rules
         and  regulations  of the  Commission  thereunder.  Such letter from the
         independent  certified public accountants shall additionally cover such
         other financial matters (including information as to periods ending not
         more than five  business  days prior to the date of such letter) as the
         Holder may reasonably request.

         If  the  Holder  exercises  its  rights  to  have  the  Warrant  Shares
registered,  it is understood  that the Holder shall furnish to the Company such
information  regarding  the  securities  held by it and the  intended  method of
disposition  thereof as the  Company  shall  reasonably  request and as shall be
required in connection with the action to be taken by the Company.

         4.4  All  Registration   Expenses   incurred  in  connection  with  any
registration pursuant to this Warrant Certificate shall be borne by the Company.
All  Selling  Expenses  in  connection  with any  registration  pursuant to this
Warrant Certificate shall be borne by the Holder.

         For purposes of Section  4.4,  all expenses  incurred by the company in
complying with Section 4.3, including,  without limitation, all registration and
filing fees, fees and expenses of complying with

                                                          -4-

<PAGE>

securities and blue sky laws,  printing expenses,  and fees and disbursements of
counsel and of independent  public  accountants  for the Company  (including the
expense of any special  audits in connection  with any such  registration),  are
herein  called  "Registration  Expenses",  and all  underwriting  discounts  and
selling  commissions  applicable  to the  Warrant  Shares  covered  by any  such
registration and all fees and disbursements of counsel for the Holder are herein
called "Selling Expenses".

         4.5 In the event of any  registration  of any Warrant  Shares under the
Securities Act pursuant to this Warrant Certificate, the Company shall indemnify
and hold  harmless the Holder,  each  underwriter  of such shares,  if any, each
broker,  and any other person, if any, who controls any of the foregoing persons
within the meaning of the Securities Act, against any losses, claims, damages or
liabilities,  joint or several, to which any of the foregoing persons may become
subject under the Securities Act or otherwise,  insofar as such losses,  claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon an  untrue  statement  or  alleged  untrue  statement  of a  material  fact
contained  in any  registration  statement  under which the Warrant  Shares were
registered  under  the  Securities  Act,  any  preliminary  prospectus  or final
prospectus  contained therein,  or any amendment or supplement  thereto,  or any
document  incident  to  registration  or  qualification  of any  Warrant  Shares
pursuant  to  paragraph  4.3(d)  above,  or arise out of or are  based  upon the
omission or alleged  omission to state  therein a material  fact  required to be
stated  therein or necessary to make the  statements  therein not misleading or,
with respect to any prospectus, necessary to make the statements therein, in the
light of the  circumstances  under which they were made, not misleading,  or any
violation by the Company of the Securities  Act or state  securities or blue sky
laws  applicable  to the Company and relating to action or inaction  required of
the  company  in  connection   with  such   registration   or   registration  or
qualification  under such state securities or blue sky laws; and shall reimburse
the Holder and such underwriter,  broker or other person acting on behalf of the
Holder  and each such  controlling  person  for any legal or any other  expenses
reasonably incurred by any of them in connection with investigating or defending
any such loss, claim, damage, liability or action;  provided,  however, that the
Company  shall not be liable in any such case to the extent  that any such loss,
claim,  damage,  or liability arises out of or is based upon an untrue statement
or alleged  untrue  statement or omission or alleged  omission  made in reliance
upon and in conformity with written  information  furnished to the Company in an
instrument duly executed by the Holder or such underwriter  specifically for use
in the preparation  thereof.  The indemnity  agreement set forth in this Section
4.5,  insofar as it  relates  to any such  omission,  alleged  omission,  untrue
statement or alleged  untrue  statement  made in a  preliminary  prospectus  but
eliminated or remedied in the final  prospectus,  shall not inure to the benefit
of any of the  beneficiaries  named in this Section 4.5 whose  responsibility it
was to  send,  furnish  or  give a copy  of the  final  prospectus  to a  person
asserting a claim for which  indemnification is sought (the "Claimant") unless a
copy of the final prospectus was so sent,  furnished or given to the Claimant at
or prior to the time such action is required by the Act.

         Before  Warrant  Shares  held or  purchasable  by the  Holder  shall be
included in any registration  pursuant to this Warrant  Certificate,  the Holder
and any underwriter acting on its behalf shall have agreed to indemnify and hold
harmless  (in the  same  manner  and to the  same  extent  as set  forth  in the
preceding paragraph) the Company,  each director of the Company, each officer of
the  Company  who shall  sign such  registration  statement  and any  person who
controls the Company within the meaning of the  Securities  Act, with respect to
any failure of the Holder or such underwriter to comply with all laws,

                                                          -5-

<PAGE>

rules and  regulations in connection  with the offer and sale of Warrant Shares,
or any statement or omission from such registration  statement,  any preliminary
prospectus or final prospectus contained therein, or any amendment or supplement
thereto,  if such  statement  or  omission  was  made in  reliance  upon  and in
conformity  with written  information  furnished to the Company in an instrument
duly  executed  by the Holder or such  underwriter  specifically  for use in the
preparation  of  such  registration  statement,  preliminary  prospectus,  final
prospectus or amendment or supplement.

         Promptly  after  receipt  by an  indemnified  party  of  notice  of the
commencement  of any  action  involving  a claim  referred  to in the  preceding
paragraphs  of this  Section 4.5,  such  indemnified  party will,  if a claim in
respect thereof is to be made against an indemnifying party, give written notice
to the indemnifying  party of the commencement of such action.  In case any such
action is brought against an indemnified  party, the indemnifying  party will be
entitled to participate in and to assume the defense  thereof,  jointly with any
other indemnifying party similarly notified to the extent that it may wish, with
counsel reasonably satisfactory to such indemnified party, and after notice from
the indemnifying  party to such  indemnified  party of its election so to assume
the  defense  thereof,  the  indemnifying  party  will  not be  liable  to  such
indemnified party for any legal or other expenses  subsequently  incurred by the
latter in connection with the defense thereof.

5.       Reservation of Warrant Shares

         The  Company  covenants  that it will at all  times  reserve  and  keep
available out of its  authorized  Common Stock,  solely for the purpose of issue
upon  exercise of the  Warrants,  such number of shares of Common Stock as shall
then be issuable  upon the  exercise of all  outstanding  Warrants.  The Company
covenants  that all shares of Common Stock which shall be issuable upon exercise
of  the  Warrants   shall  be  duly  and  validly  issued  and  fully  paid  and
non-assessable  and free from all taxes,  liens and charges  with respect to the
issue thereof.

6.       Loss or Mutilation

         Upon receipt by the Company of reasonable  evidence of the ownership of
and the loss, theft,  destruction or mutilation of any Warrant  Certificate and,
in the case of loss, theft or destruction,  of indemnity reasonably satisfactory
to the Company,  or, in the case of mutilation,  upon surrender and cancellation
of the mutilated Warrant  Certificate,  the Company shall execute and deliver in
lieu thereof a new Warrant Certificate representing an equal number of Warrants.

7.       Adjustment of Purchase Price and Number of Warrant Shares Deliverable

         7.1 The  Purchase  Price and the  number  of  shares  of  Common  Stock
purchasable pursuant to this Warrant shall be subject to adjustment from time to
time as hereinafter  set forth in this Article 7. Whenever  reference is made in
this Article 7 to the issue or sale of shares of Common Stock, or simply shares,
such term shall mean any stock of any class of the Company other than  preferred
stock with a fixed limit on dividends and a fixed amount payable in the event of
any  voluntary  or  involuntary  liquidation,  dissolution  or winding up of the
Company. The shares issuable upon exercise of the

                                                          -6-

<PAGE>

Warrants  shall  however  be shares of Common  Stock of the  Company,  par value
$0.001  per  share,  as  constituted  at the date  hereof,  except as  otherwise
provided in Sections 7.3 and 7.4.

         7.2 In case  the  Company  shall  at any time  change  as a  whole,  by
subdivision or  combination in any manner or by the making of a stock  dividend,
the number of  outstanding  shares  into a different  number of shares,  with or
without  par value,  (i) the number of shares  which  immediately  prior to such
change the holder of each Warrant shall have been entitled to purchase  pursuant
to this Warrant  shall be increased  or  decreased in direct  proportion  to the
increase  or  decrease,  respectively,  in  the  number  of  shares  outstanding
immediately  prior  to such  change,  and  (ii) the  Purchase  Price  in  effect
immediately  prior to such change  shall be  increased  or  decreased in inverse
proportion to such increase or decrease in the number of such shares outstanding
immediately  prior to such  change.  For the purpose of this  Section  7.2,  the
number of shares  outstanding  at any given time shall not include shares in the
treasury of the Company.

         7.3 In case of any capital  reorganization or any  reclassification  of
the capital  stock of the Company or in case of the  consolidation  or merger of
the Company with another corporation,  or in case of any sale, transfer or other
disposition  to another  corporation of all or  substantially  all the property,
assets,  business and good will of the Company, the holder of each Warrant shall
thereafter  be  entitled  to  purchase  (and  it  shall  be a  condition  to the
consummation  of  any  such  reorganization,  reclassification,   consolidation,
merger, sale, transfer or other disposition that appropriate  provision shall be
made so that such holder shall  thereafter be entitled to purchase) the kind and
amount of shares of stock and other  securities and property  receivable in such
transaction  which a  shareholder  receives who holds the number of shares which
the Warrant  entitled the holder to purchase  immediately  prior to such capital
reorganization,  reclassification of capital stock, consolidation, merger, sale,
transfer  or other  disposition;  and in any such case  appropriate  adjustments
shall  be made in the  application  of the  provisions  of this  Article  7 with
respect to rights and interests  thereafter of the holder of the Warrants to the
end that the  provisions of this Article 7 shall  thereafter be  applicable,  as
nearly  as  reasonably  may be, in  relation  to any  shares  or other  property
thereafter purchasable upon the exercise of the Warrants.

         7.4 In the event the Company  shall  declare a dividend upon the Common
Stock payable otherwise than out of earnings or earned surplus or otherwise than
in shares of Common  Stock or in stock or  obligations  directly  or  indirectly
convertible  into or  exchangeable  for such shares,  the holder of each Warrant
shall, upon exercise of the Warrant, be entitled to purchase, in addition to the
number of shares deliverable upon such exercise,  against payment of the Warrant
Price  therefor  but without  further  consideration,  the cash,  stock or other
securities  or property  which the holder of the Warrant  would have received as
dividends  (otherwise  than out of such earnings or earned surplus and otherwise
than in shares or in obligations  convertible  into or  exchangeable  for Common
Stock) if continuously since the date hereof such holder (i) had been the holder
of record of the number of shares  deliverable  upon such  exercise and (ii) had
retained all dividends in stock or other  securities  (other than shares or such
convertible or exchangeable  stock or obligations) paid or payable in respect of
said  number of shares or in respect of any such  stock or other  securities  so
paid or payable as such dividends.

         7.5 No certificate for fractional  shares  shall  be  issued  upon  the
exercise of the Warrants, but
                                                          -7-
<PAGE>

in lieu  thereof  the  Company  shall  purchase  any  such  fractional  interest
calculated to the nearest cent.

         7.6  Whenever the Purchase  Price is adjusted as herein  provided,  the
Company shall forthwith deliver to each Warrant holder a statement signed by the
President of the Company and by its Treasurer or Secretary  stating the adjusted
Purchase  Price and  number  of shares  determined  as  herein  specified.  Such
statement shall show in detail the facts requiring such adjustment,  including a
statement of the consideration  received by the Company for any additional stock
issued.

         7.7      In the event at any time:

                  (i) The Company  shall pay any dividend  payable in stock upon
                  its Common  Stock or make any  distribution  (other  than cash
                  dividends) to the holders of its Common Stock; or

                  (ii)     The Company shall offer for subscription pro rata  to
                  the holders of its Common Stock any additional shares of stock
                  of any class or any other rights; or

                  (iii) The Company shall effect any capital  reorganization  or
                  any  reclassification  of or change in the outstanding capital
                  stock of the Company  (other than a chance in par value,  or a
                  change from par value to no par value, or a change from no par
                  value  to par  value,  or a  change  resulting  solely  from a
                  subdivision  or combination  of  outstanding  shares),  or any
                  consolidation  or  merger,  or any  sale,  transfer  or  other
                  disposition of all or substantially all its property,  assets,
                  business  and good will as an  entirety,  or the  liquidation,
                  dissolution or winding up of the Company; or

                  (iv) The  Company  shall  declare a  dividend  upon its Common
                  Stock payable otherwise than out of earnings or earned surplus
                  or otherwise  than in Common Stock or any stock or obligations
                  directly or indirectly  convertible  into or exchangeable  for
                  Common Stock;

then,  in any such case,  the Company  shall cause at least  thirty  days' prior
notice to be mailed to the  registered  holder of each Warrant at the address of
such holder  shown on the books of the  Company.  Such notice shall also specify
the date on which the books of the Company  shall  close,  or a record be taken,
for such stock dividend,  distribution or  subscription  rights,  or the date on
which  such  reclassification,   reorganization,  consolidation,  merger,  sale,
transfer, disposition,  liquidation, dissolution, winding up or dividend, as the
case may be,  shall take  place,  and the date of  participation  therein by the
holders of shares if any such date is to be fixed, and shall also set forth such
facts with  respect  thereto as shall be  reasonably  necessary  to indicate the
effect of such action on the rights of the holders of the Warrants.

                                                          -8-

<PAGE>

8.       Governing Law

         8.1      This Warrant Certificate shall be governed by and construed in
accordance with the laws of the State of Delaware.

         IN WITNESS WHEREOF,  the Company has caused this Warrant Certificate to
be duly executed by its officers  thereunto  duly  authorized  and its corporate
seal to be affixed hereon as of the 5th day of October, 1999.

                                                          PREFERRED VOICE, INC.


                                                          BY:/s/
                                                          ----------------------
                                                          Chairman of the Board

Attest:


/s/
--------------------------
Secretary

                                                          -9-