AMENDED GUARANTY

     AMENDMENT TO GUARANTY ("AMENDMENT"), dated as of ___________, 2000, made by
and  between  HORIZON  TELCOM,  INC.  (hereinafter  called the  "Guarantor"),  a
corporation  existing  under the laws of the  State of Ohio and RURAL  TELEPHONE
FINANCE  COOPERATIVE  (hereinafter  sometimes  called the "Lender" and sometimes
called the "RTFC"), a South Dakota cooperative association.

     WHEREAS,  Guarantor  previously executed and delivered to Lender a guaranty
(the  "Guaranty")  dated August 29, 1997,  guaranteeing  certain  obligations of
Guarantor's  wholly-owned  subsidiary,  HORIZON  PERSONAL  COMMUNICATIONS,  INC.
("Borrower")  under a loan  agreement and a promissory  note  (collectively  the
"1997 Loan  Documents"),  each dated August 29, 1997 and designated OH 803-A-01,
between  Borrower  and  Lender  providing  for an  extension  of  credit  in the
principal amount of $23,557,965; and

     WHEREAS,  the  Borrower is a party to a certain Loan  Agreement  (the "2000
Loan Agreement") dated ___________________,  2000 by and between itself and RTFC
providing for an extension of credit as evidenced by a secured  promissory  note
(the "2000 Note") designated OH 803-9002 in the principal amount of $40,500,000;
and

     WHEREAS,  under the  terms of the 2000 Loan  Agreement,  the  extension  of
credit  and  advancement  of funds  called  for in the 2000  Loan  Agreement  is
conditioned upon this amendment of the Guaranty;

     NOW THEREFORE,  to induce Lender to make the extension of credit called for
in the 2000 Loan Agreement and the benefits derived by the Guarantor  therefrom,
and in  satisfaction  of a material  condition  precedent  to such  extension of
credit  by the  Lender,  the  parties  agree to amend  the  Guaranty  to read as
follows:

1.   For and in consideration  of loans,  advances,  acceptances,  discounts and
     extensions  of  credit  made by  RURAL  TELEPHONE  FINANCE  COOPERATIVE,  a
     cooperative  organized and existing  under the laws of South Dakota ("RTFC"
     or  "Lender"),  to, for the  account  of, or on behalf of HORIZON  PERSONAL
     COMMUNICATIONS, INC. a corporation organized and existing under the laws of
     Ohio ("Borrower") (the documents evidencing such obligations of Borrower to
     RTFC  pursuant to (i) a loan  agreement and a promissory  note,  each dated
     August 29, 1997;  and (ii) a loan  agreement  and a promissory  note,  each
     dated , 2000 are hereinafter called the "Loan Documents"), the undersigned,
     HORIZON TELCOM,  INC., a corporation  organized and existing under the laws
     of Ohio ("Guarantor"),  hereby absolutely and unconditionally guarantees to
     RTFC the punctual  payment in full of an amount not to exceed the lesser of
     : (a) the aggregate  principal amount of $7,852,655 (United States dollars)
     plus  interest  due  thereon,  or  (b)  12.26%  of  Borrower's  outstanding
     principal  indebtedness plus interest due thereon under the Loan Documents,
     from  the  date  hereof  until  the  termination  of the  liability  of the
     Guarantor  hereunder  as  hereinafter  provided,  on account of any and all
     obligations, indebtedness and liability of the Borrower to RTFC pursuant to
     the Loan  Documents,  whether now existing or hereafter  incurred,  whether
     direct,  indirect,  or  contingent,  and whether  otherwise  guaranteed  or
     secured, (such obligations, indebtedness and liability pursuant to the Loan
     Documents are hereinafter referred to as "Indebtedness").

2.   The Guarantor further agrees to pay Lender its pro-rata portion (12.26%) of
     any and all costs, expenses and reasonable attorneys' fees paid or incurred
     by Lender in collecting or endeavoring to collect the  Indebtedness  of the
     Borrower,  and all costs,  expenses and reasonable  attorneys' fees paid or
     incurred  in  enforcing   or   endeavoring   to  enforce   this   Guaranty.
     Notwithstanding anything to the contrary herein, the Guarantor shall not be
     liable for any expenses  incurred in Lender's  endeavoring to collect under
     the guaranty provided by Motorola, Inc. pursuant to the Loan Documents.

3.   The Lender may, at the Lender's  option,  proceed to enforce this  Guaranty
     directly against the Guarantor (and any collateral securing  performance of
     this Guaranty owned by the Guarantor)  without first proceeding against the
     Borrower,  any  co-guarantor,  or any other  person  liable for  payment or
     performance  under the Loan Documents and without first proceeding  against
     or exhausting  any collateral now or hereafter held by the Lender to secure
     payment or performance under the Loan Documents.

4.   The Guarantor waives diligence,  presentment,  protest, notice of dishonor,
     demand for payment,  notice of nonpayment or nonperformance,  notice of the
     incurrence  of  indebtedness  by  Borrower,  notice of  acceptance  of this
     Guaranty  and all  other  notices  of any  nature  in  connection  with the
     exercise of the Lender's  rights under the Loan Documents or this Guaranty.
     Performance  by the Guarantor  hereunder  will not entitle the Guarantor to
     any   payment   by  the   Borrower   under  any  claim  for   contribution,
     indemnification,   subrogation  or  otherwise,   until  such  time  as  all
     Indebtedness  owing to the Lender has been paid.  The Guarantor  waives the
     right to require  Lender to file suit  against  the  Borrower  or any other
     party  before  enforcing  this  Guaranty,  and all  rights to  setoffs  and
     counterclaims  against  the Lender and agrees that any  subrogation  rights
     which the  Guarantor  might now or hereafter  hold against the Borrower and
     any  co-guarantors  will be subordinate,  junior and inferior to all rights
     which the Lender might now or  hereafter  hold against the Borrower and any
     co-guarantors.

5.   The Guarantor  hereby  consents and agrees that renewals and  extensions of
     time of payment, surrender, release, exchange,  substitution,  dealing with
     or taking of  additional  collateral  security,  taking or release of other
     guarantees,  abstaining  from taking  advantage  of or  realizing  upon any
     collateral  security or other guarantees and any and all other forbearances
     or indulgences  granted by Lender to the Borrower or any other party may be
     made,  granted and effected by Lender  without  notice to the Guarantor and
     without in any manner affecting its liability hereunder.

6.   Nothing  herein  contained  shall limit the Lender in exercising any rights
     held  under  any one or more of the  Loan  Documents.  In the  event of any
     default  under the Loan  Documents  or this  Guaranty,  the Lender  will be
     entitled to  selectively  and  successively  enforce any one or more of the
     rights  held by the Lender and such  action  will not be deemed a waiver of
     any other  rights  held by the  Lender.  All of the  remedies of the Lender
     under  this  Guaranty  and  the  Loan  Documents  are  cumulative  and  not
     alternative. If the Lender elects to foreclose any lien created by the Loan
     Documents,  the Lender is authorized  to purchase for the Lender's  account
     all or any part of the collateral covered by such lien at public or private
     sale and to credit the amount  recovered  first  against any portion of the
     Indebtedness  for which the Guarantor is liable with any balance  remaining
     to be applied in reduction of the liability of the Guarantor hereunder.

7.   In the  event  that a  petition  in  bankruptcy  or for an  arrangement  or
     reorganization  of the  Borrower  under  the  bankruptcy  laws  or for  the
     appointment  of a receiver for the Borrower or any of its property is filed
     by or against the Borrower, or if the Borrower shall make an assignment for
     the benefit of creditors or shall become insolvent, all Indebtedness of the
     Borrower  shall,  for the purpose of this  Guaranty,  be deemed at Lender's
     election to have become immediately due and payable.

8.   Guarantor hereby represents and warrants that:

     a.   Good  Standing.  Guarantor is a corporation  duly  organized,  validly
          existing and in good standing under the laws of the State of Ohio, has
          the power to own its  property and to carry on its  business,  is duly
          qualified to do business, and is in good standing in each jurisdiction
          in which the  transaction  of its  business  makes such  qualification
          necessary.

     b.   Authority.  Guarantor has the  corporate  power and authority to enter
          into  this  Guaranty,   to  execute  and  deliver  all  documents  and
          instruments   required  hereunder,   and  to  incur  and  perform  the
          obligations   provided  for  herein,  all  of  which  have  been  duly
          authorized by all necessary and proper corporate and other action.

     c.   Other  Obligations.  The aggregate  amount of  obligations  guaranteed
          hereunder  shall not  exceed  the  maximum  amount  allowed  under any
          mortgage,  indenture  or  agreement  of any  kind  entered  into by or
          affecting the Guarantor at the time Lender may seek payment under this
          Guaranty.

9.   Guarantor  covenants  and  agrees  with  Lender  that,  until  all  of  the
     obligations guaranteed hereunder shall have been satisfied in full:

     a.   Control. The Guarantor will not merge, consolidate,  liquidate,  alter
          or otherwise permit alteration of control of the Guarantor without the
          prior  written  consent  of  Lender.  Control  shall be as  defined by
          regulations   for   telephone   companies   issued   by  the   Federal
          Communications Commission.

     b.   Additional  Indebtedness.  The  Guarantor  will not borrow  money on a
          secured or  unsecured  basis from any other lender  without  obtaining
          Lender's  prior  written  consent.  Furthermore,  no subsidiary of the
          Guarantor  will borrow money on a secured or unsecured  basis from any
          other   lender,   or  incur  any   additional   secured  or  unsecured
          Indebtedness,  or enter into any Leases, unless at that time Guarantor
          and its  subsidiaries  shall have a consolidated Net Worth equal to or
          greater than forty percent (40%); provided, however, Guarantor and its
          subsidiaries  may grant purchase money secured  indebtedness  or incur
          unsecured trade debt or pay other current  operating  liabilities that
          arise in the  ordinary  course of  business  so long as the  aggregate
          total of such debt does not exceed five  percent  (5%) of  Guarantor's
          consolidated   total  assets.   If  Guarantor  and  its  subsidiaries'
          consolidated  Net Worth exceeds forty percent (40%),  then Guarantor's
          subsidiaries  may incur additional  Guarantor's  Indebtedness or enter
          into Leases  without prior  written  approval of Lender so long as the
          Guarantor   and  its   subsidiaries   meet  the  forty  percent  (40%)
          consolidated   Net  Worth  test  after   incurring   such   additional
          Guarantor's  Indebtedness  or  entering  into such  Leases;  provided,
          further,  however,  Guarantor's  subsidiary  must give at least thirty
          (30) days written notice to Lender prior to incurring or entering into
          any additional  Leases or term loans,  guarantees,  lines of credit or
          other third-party credit facilities.  Notwithstanding  anything to the
          contrary herein,  without Lender's prior written consent,  Guarantor's
          subsidiary, The Chillicothe Telephone Company ("Chillicothe"), will be
          able  to  incur   additional   secured   indebtedness   and  unsecured
          indebtedness   not  to  exceed  ten  percent  (10%)  of  Chillicothe's
          stand-alone  total assets  provided  that  Chillicothe:  (i) meets the
          forty percent (40%) unconsolidated Net Worth test after incurring such
          additional  indebtedness;   (ii)  has  a  current  assets  to  current
          liabilities   ratio   of  1.10   after   incurring   such   additional
          indebtedness;  and (iii) along with  Guarantor are in compliance  with
          all of their loan and guaranty  documents  with  Lender.  Furthermore,
          Lender hereby  expressly  acknowledges,  and agrees to except from the
          preceding  calculations,  Chillicothe's  conversion  of  $4,000,000 of
          short-term  debt to  long-term  debt  and  its  proposed  addition  of
          $6,000,000  of  long-term  switch  financing as presented to Lender in
          conjunction with Borrower's proposed financing.

          For purposes of this  Guaranty,  unless stated  otherwise  "Net Worth"
          shall be calculated on a consolidated  basis for Guarantor and all its
          subsidiaries,   and  shall  be  calculated  by  dividing   equity  (as
          determined  by  subtracting  total  liabilities  from total assets) by
          total assets.  For purposes of this Guaranty,  "Leases" shall mean any
          lease of property by which Guarantor or any of its subsidiaries  shall
          be obligated for rental or other  payments which  individually  are in
          excess of  $50,000  per  year,  or in the  aggregate  are in excess of
          $1,500,000  per year.  For  purposes  of this  Guaranty,  "Guarantor's
          Indebtedness" shall include all items which would properly be included
          in the  liability  section of a balance  sheet or in a  footnote  to a
          financial statement,  in accordance with generally accepted accounting
          principles including, without limitation, contingent liabilities.

     c.   Dividends and Other Cash Distributions. The Guarantor will not, in any
          one fiscal year,  without the prior  approval in writing of the Lender
          (i) declare or pay any dividends or make any other distribution to its
          stockholders  with  respect to its  capital  stock;  (ii)  purchase or
          redeem or retire any of its capital stock; or (iii) pay any management
          fees or if  already  paying  a  management  fee,  pay an  increase  in
          management  fees unless with  respect to any of the  foregoing  (after
          giving effect to such transaction)  Guarantor's Net Worth shall exceed
          twenty five percent (25%); provided,  however,  without Lender's prior
          written consent, Guarantor may make dividend payments or distributions
          equal to its prevailing  consolidated  net income so long as the total
          amount of  dividends  paid by  Guarantor in any given fiscal year does
          not exceed $1,914,779.

     d.   Sale of Assets.  The Guarantor and any subsidiary of the Guarantor may
          not,  without prior  written  approval of the Lender,  sell,  lease or
          transfer  any asset unless the fair market value of such asset is less
          than 1% of  Guarantor's  consolidated  total assets and the  aggregate
          value of assets sold,  leased or transferred in any 12-month period is
          less than 5% of Guarantor's consolidated total assets. Notwithstanding
          anything to the contrary herein,  Guarantor and its subsidiaries  may:
          (i)  sell  securities  issued  or  guaranteed  by  the  United  States
          government or any agency or instrumentality  thereof, or securities or
          obligations of institutions  whose senior  unsecured debt  obligations
          are rated by at least two nationally  recognized ratings organizations
          in either  of its two  highest  categories;  and (ii)  sell,  lease or
          transfer  inventory,  customer  premise  equipment and PABX equipment.
          Notwithstanding  anything to the contrary  herein,  Guarantor  may not
          sell, transfer,  encumber or otherwise convey any of its voting Common
          Stock in Chillicothe.

     e.   Financial Reports and Other  Information.  The Guarantor will furnish,
          in form and substance  satisfactory to Lender: (a) a full and complete
          report of Guarantor's  and its  subsidiaries'  financial  condition at
          least once during each  12-month  period during the term hereof but in
          no event  later  than 120 days  after the end of each  fiscal  year of
          Guarantor,   which  shall  include  (i)  annual  financial  statements
          prepared on a  consolidated  basis and audited by  independent  public
          accountants selected by Guarantor and reasonably acceptable to Lender,
          accompanied by an opinion of such accountants reasonably acceptable to
          Lender, and (ii) unaudited annual  consolidating  financial statements
          of Guarantor and its subsidiaries; (b) within 120 days of the close of
          each  calendar  year, a written  statement  signed by the  Guarantor's
          president,  chief  executive  officer  or  similar  presiding  officer
          stating that to the best of said person's knowledge that the Guarantor
          has fulfilled all of its obligations hereunder or, if there has been a
          default in the  fulfillment of any such  obligations,  specifying each
          such default  known to such person and the nature and status  thereof;
          and (c) such other information,  reports or statements  concerning the
          operations,  business affairs and/or financial  condition of Guarantor
          and its subsidiaries as the Lender may reasonably request from time to
          time.

     f.   Financial  Books;  Lender  Right  of  Inspection:  Guarantor  and  its
          subsidiaries  will at all times  keep,  and  safely  preserve,  proper
          books,  records and  accounts in which full and true  entries  will be
          made of all of the dealings, business and affairs of the Guarantor, in
          accordance  with  methods  of  accounting   prescribed  by  the  state
          regulatory  body having  jurisdiction  over the  Guarantor,  or in the
          absence of such  regulatory body or such  prescription,  in accordance
          with generally accepted accounting principles. The Lender, through its
          representatives,  shall at all times during reasonable  business hours
          have  access to, and the right to inspect  and make  copies of, any or
          all books, records and accounts,  and any or all invoices,  contracts,
          leases, payrolls,  canceled checks, statements and other documents and
          papers of every kind  belonging to or in  possession  of the Guarantor
          and  its  subsidiaries  and  pertaining  to the  Guarantor's  and  its
          subsidiaries' property or business.

     g.   Loans, Investments and Other Obligations:  (a) The Guarantor will not,
          without first obtaining the written  approval of Lender:  (i) purchase
          or make any commitment to purchase any stock, bonds, notes, debentures
          or other securities or obligations of or beneficial interests in, (ii)
          make any  other  investments  in,  (iii)  make  any  loan to,  or (iv)
          guarantee,  assume,  or otherwise become liable for any obligation of,
          any  corporation,  association,  partnership,  joint  venture,  trust,
          government or any agency or department thereof, or any other entity of
          any kind if the aggregate  amount of all such purchases,  investments,
          loans and guarantees exceeds the greater of ten percent (10%) of Total
          Plant or thirty  percent  (30%) of Net  Worth.  For  purposes  of this
          Guaranty,  "Total Plant" shall be calculated on a  consolidated  basis
          for the Guarantor and all its subsidiaries and shall mean the total of
          all assets  included  in  property,  plant and  equipment  pursuant to
          generally  accepted  accounting   principles  and  shall  exclude  any
          goodwill or plant acquisition adjustments. (b) The following shall not
          be included in the  limitation  on purchases,  investments,  loans and
          guarantees in (a) above: (i) bonds, notes, debentures, stock, or other
          securities or obligations issued by or guaranteed by the United States
          government  or any  agency or  instrumentality  thereof;  (ii)  bonds,
          notes,  debentures,  stock,  commercial  paper,  subordinated  capital
          certificates,  or any other  security or  obligation  of  institutions
          whose  senior  unsecured  debt  obligations  are rated by at least two
          nationally  recognized  rating  organizations  in  either  of its  two
          highest  categories;  (iii)  investments  incidental  to loans made by
          RTFC;   (iv)  any  deposit  that  is  fully  insured  by  the  Federal
          Government;  and (v)  common  stock or  other  equity  investments  in
          Borrower.  For purposes of this section,  securities  and  investments
          shall be  calculated at cost and exclude any cash  surrender  value of
          life insurance.

10.  If the Guarantor fails to make any payment  pursuant to Lender's demand for
     payments provided for in Sections 1 and 2 hereunder,  then a "Payment Event
     of Default" shall have been deemed to occur  hereunder and then Lender may,
     upon five (5) days written  notice (with a copy of such notice to Borrower)
     during which time  Guarantor or Borrower  shall have the right to cure such
     Payment  Event of Default,  in addition to any other  rights  available  to
     Lender at law or in  equity,  declare  the  maximum  amount  guaranteed  by
     Guarantor  at such  time  pursuant  to  Sections  1 and 2  hereunder  to be
     immediately due and payable without presentment,  demand, protest or notice
     of any kind, all of which are hereby expressly waived.  Any funds collected
     hereunder  shall be  immediately  applied as a  prepayment  (subject to any
     applicable prepayment fees) pro-ratably to all of Borrower's Indebtedness.

11.  If the  Guarantor  fails to observe or perform  any  warranty,  covenant or
     condition  under  Section 9 of this  Guaranty,  then a  "Covenant  Event of
     Default" shall have been deemed to occur hereunder.  Upon the occurrence of
     a Covenant  Event of  Default,  the Lender may  provide  written  notice to
     Guarantor  (with a copy of such notice to  Borrower) of the  occurrence  of
     said  Covenant  Event of Default  and demand  that such  Covenant  Event of
     Default be cured within thirty (30) days of receipt of such notice. If such
     Covenant  Event of  Default  is not  cured by  Guarantor,  or a  substitute
     guarantor is not approved in writing by Lender  within such thirty (30) day
     cure period,  then Lender may, in addition to any other rights available to
     Lender at law or in equity,  declare a "Payment Event of Default" and, upon
     five (5) days  written  notice  (with a copy of such  notice  to  Borrower)
     during which time  Guarantor or Borrower  shall have the right to cure such
     Payment  Event of  Default,  so declare the maximum  amount  guaranteed  by
     Guarantor  at such  time  pursuant  to  Sections  1 and 2  hereunder  to be
     immediately due and payable without presentment,  demand, protest or notice
     of any kind, all of which are hereby expressly waived.  Any funds collected
     hereunder  shall be  immediately  applied as a  prepayment  (subject to any
     applicable prepayment fees) pro-ratably to all of Borrower's Indebtedness.

12.  If any  provision  of  this  Guaranty  is held to be  invalid,  illegal  or
     unenforceable   in  any  respect  or  application  for  any  reason,   such
     invalidity,  illegality  or  unenforceability  will not  affect  any  other
     provisions  herein  contained and such other provisions will remain in full
     force and effect.

13.  If any  payment or thing of value  should be received  and  accepted by the
     Lender in payment of any  Indebtedness  or obligation of the Borrower under
     any of the Loan  Documents  and it should  subsequently  be  determined  or
     adjudged that such payment be void or voidable under any law or statute now
     or hereafter in effect the receipt of such payment by the Lender shall,  as
     to the Guarantor,  be deemed a provisional  receipt and if any such payment
     should be avoided or set aside under any such law or statute the  Guarantor
     shall be and  remain  liable to the  Lender in  respect  thereof as if such
     payment had not been received by the Lender  notwithstanding any release or
     discharge of this Guaranty to the Guarantor issued or granted by the Lender
     in the belief or  assumption  that its receipt of such payment was absolute
     and not subject to any avoidance.

14.  THIS  GUARANTY  WILL  BE  CONSTRUED  IN  ACCORDANCE  WITH  THE  LAWS OF THE
     COMMONWEALTH  OF VIRGINIA.  GUARANTOR  HEREBY  SUBMITS TO THE  NONEXCLUSIVE
     JURISDICTION  OF THE  COURTS OF THE  UNITED  STATES  COURTS  LOCATED IN THE
     COMMONWEALTH OF VIRGINIA FOR PURPOSES OF ALL LEGAL PROCEEDINGS  ARISING OUT
     OF OR RELATING TO THIS GUARANTY OR THE  TRANSACTIONS  CONTEMPLATED  HEREBY.
     GUARANTOR  IRREVOCABLY WAIVES TO THE FULLEST EXTENT PERMITTED BY APPLICABLE
     LAW, ANY OBJECTION THAT IT MAY NOW OR HEREAFTER HAVE TO THE ESTABLISHING OF
     THE VENUE OF ANY SUCH PROCEEDING BROUGHT IN SUCH A COURT AND ANY CLAIM THAT
     ANY SUCH PROCEEDING HAS BEEN BROUGHT IN AN INCONVENIENT  FORUM. EACH OF THE
     GUARANTOR AND THE LENDER HEREBY  IRREVOCABLY  WAIVES, TO THE FULLEST EXTENT
     PERMITTED  BY  APPLICABLE  LAW,  ANY AND ALL  RIGHT TO TRIAL BY JURY IN ANY
     LEGAL  PROCEEDING  ARISING  OUT OF OR  RELATING  TO  THIS  GUARANTY  OR THE
     TRANSACTIONS CONTEMPLATED HEREBY.

15.  This Guaranty  shall be binding upon the Guarantor and its  successors  and
     assigns,  and shall  inure to the  benefit of RTFC and its  successors  and
     assigns.  This  Guaranty  may be  transferred  or assigned by  Guarantor to
     another entity of equal or greater credit quality than Guarantor so long as
     RTFC  provides its prior written  consent to such  transfer or  assignment,
     which consent shall not be unreasonably withheld.

16.  All accounting terms not specifically defined herein shall have the meaning
     assigned to them by generally accepted accounting principles.

17.  This Guaranty shall operate as a continuing  guaranty and shall expire only
     upon the  satisfaction by Borrower,  Guarantor,  or any co-guarantor of all
     obligations owed by Borrower to RTFC under the Loan Documents.

18.  On or  prior to the  initial  advance  under  the 2000  Loan  Agreement  to
     Borrower,   Guarantor   covenants   to  enter  into   revised  firm  equity
     subscription  agreements  with Borrower,  in form and substance  reasonably
     satisfactory to Lender,  that provide for additional  common equity capital
     contributions  from  Guarantor  in the  minimum  amounts  set  forth  below
     opposite the corresponding date.


                   Date                            Amount

                At closing                      $15,106,203

             December 31, 2000                   1,500,000

             December 31, 2001                   1,000,000

             December 31, 2002                   1,000,000

     The revised equity  subscription  agreement  shall also provide that it may
     not be  modified,  transferred,  or  terminated  by  either  party  without
     Lender's  prior  written  consent and the Lender  shall be named as a third
     party beneficiary with regard to enforcing payments under that agreement.

19.  On or  prior  to the  date of the  initial  advance  under  the  2000  Loan
     Documents  to  Borrower,  Guarantor  covenants  to enter into a tax sharing
     arrangement  with Borrower,  in form and substance  satisfactory to Lender,
     that  provides  for the pass  through to Borrower  of tax  benefits as cash
     payments  equal to the lesser of (i) the amounts  set forth below  opposite
     the corresponding  date, or (ii) a positive dollar amount equivalent to 34%
     of the Borrower's book net loss.


                   Date                            Amount

             December 31, 2000                   $4,522,000

             December 31, 2001                   $4,619,000

             December 31, 2002                   $1,196,000

     To the extent that Borrower  and/or  Guarantor do not have final net income
     calculations  by December  31st of any given year,  such parties  shall use
     their best efforts to provide an estimated cash payment in accordance  with
     the above schedule by December 31st of said year; thereafter,  based on the
     latest  available tax  information but in no event later than March 31st of
     the following year, a "true-up" calculation shall be made whereby Guarantor
     shall provide  Borrower an additional  cash payment in accordance  with the
     above schedule (if the December 31st  contribution was  underestimated)  or
     Borrower at Guarantor's option shall provide Guarantor a refund payment (if
     the December 31st  contribution  was  overestimated).  Notwithstanding  the
     timing of any  true-ups  and  whenever the years final tax return is filed,
     Guarantor  shall  continue  to be  liable  for any  necessary  payments  in
     accordance with the above schedule.

     The revised tax sharing  agreement  shall also  provide  that it may not be
     modified, transferred, or terminated by either party without Lender's prior
     written consent and the Lender shall be named as a third party  beneficiary
     with regard to enforcing payments under that agreement.

20.  The Guarantor hereby states, and RTFC hereby expressly  acknowledges,  that
     this  Guaranty is not  collateralized  by either the stock or the assets of
     Guarantor's wholly-owned subsidiary, The Chillicothe Telephone Company.

21.  Whenever  prior  approval  or  consent  is  required  under  the  terms and
     conditions of this Guaranty,  RTFC agrees to not  unreasonably  withhold or
     delay such approval or consent.


     IN WITNESS  WHEREOF,  this Guaranty has been executed and delivered by RTFC
and the undersigned Guarantor as of the _______ day of __________________, 2000.


                                        HORIZON TELCOM, INC.

(SEAL)                                  By:_______________________________

                                        Title:____________________________

                                        Address: 68 East Main Street
                                                 Chillicothe, OH  45601
                                                 Fax:  (614) 774-3400


Attest:_________________________
                  (Secretary)


                                        RURAL TELEPHONE FINANCE
                                        COOPERATIVE

(SEAL)                                  By:______________________________

                                        Title:___________________________

                                        Address:  Woodland Park
                                                  2201 Cooperative Way
                                                  Herndon, Virginia  20171-3025
                                                  Fax:  (703) 709-6776

Attest:__________________________
                  (Secretary)