As filed with the Securities and Exchange Commission on July 8, 2003
                                                     Registration No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                   ----------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                   ----------
                             INTER-TEL, INCORPORATED
             (Exact name of Registrant as specified in its charter)
                                   ----------
                                   1615 S. 52nd Street
            Arizona                  Tempe, AZ 85281          86-0220994
(State or other jurisdiction of   (Address of principal     (I.R.S. Employer
 incorporation or organization)     executive offices)    Identification Number)
                                   ----------
     Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement Trust
                            (Full title of the plan)
                                   ----------
                                Steven G. Mihaylo
         Chairman of the Board of Directors and Chief Executive Officer
                             INTER-TEL, INCORPORATED
                               1615 S. 52nd Street
                                    Tempe, AZ
                     (Name and address of agent for service)
                                   ----------
                                 (480) 449-8900
          (Telephone number, including area code, of agent for service)
                                   ----------
                                   COPIES TO:

                               Robert G. Day, Esq.
                               Caine T. Moss, Esq.
                        Wilson Sonsini Goodrich & Rosati
                            Professional Corporation
                               650 Page Mill Road
                               Palo Alto, CA 94304
                                 (650) 493-9300
                                   ----------
                         CALCULATION OF REGISTRATION FEE


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                                                                   Proposed Maximum    Proposed Maximum
                                                                  Offering Price Per  Aggregate Offering      Amount of
Title of Securities to be Registered     Amount to be Registered         Share               Price        Registration Fee
--------------------------------------------------------------------------------------------------------------------------
                                                                                                  
Common Stock, $.0001 par value,
  available for issuance under the
  Inter-Tel, Incorporated Tax Deferred
  Savings Plan and Retirement Trust...        2,000,000(1)             $21.17(2)          $42,340,000         $3,425.31
--------------------------------------------------------------------------------------------------------------------------
TOTAL.................................        2,000,000                                                       $3,425.31
==========================================================================================================================

(1)  Pursuant to Rule 416(c) under the Securities Act of 1933, as amended this
     registration statement covers an indeterminate amount of interests to be
     offered or sold pursuant to the Inter-Tel, Incorporated Tax Deferred
     Savings Plan and Retirement Trust described herein.
(2)  Estimated in accordance with Rule 457(h) solely for the purpose of
     calculating the registration fee, based on the average of the high and low
     price per share of the common stock as reported on the Nasdaq National
     Market on July 1, 2003.

================================================================================

                             INTER-TEL, INCORPORATED

                       REGISTRATION STATEMENT ON FORM S-8

                                     PART I

                     INFORMATION REQUIRED IN THE PROSPECTUS

ITEM 1. PLAN INFORMATION

     Omitted pursuant to the instructions and provisions of Form S-8.

ITEM 2. REGISTRATION INFORMATION AND ANNUAL EMPLOYEE INFORMATION

     Omitted pursuant to the instructions and provisions of Form S-8.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE

     Inter-Tel,  Incorporated (the "Registrant") and the Inter-Tel, Incorporated
Tax Deferred Savings Plan and Retirement  Trust (the "Plan") hereby  incorporate
by reference  into this  Registration  Statement  the  following  documents  and
information  heretofore  filed with the Securities and Exchange  Commission (the
"SEC"):

     (a)  The Registrant's Annual Report on Form 10-K filed with the SEC for the
year ended December 31, 2002.

     (b)  The Registrant's  Quarterly Report on Form 10-Q filed with the SEC for
the three months ended March 31, 2003 and the  Registrant's  reports on Form 8-K
filed with the SEC on April 7, 2003 and April 22, 2003.

     (c)  The  description  of the  Registrant's  Common Stock  contained in the
Registrant's  Registration  Statement on Form 8-A dated February 26, 1982, filed
pursuant  to Section 12 of the  Securities  Exchange  Act of 1934,  as  amended,
including  any  amendment  or report  filed for the  purpose  of  updating  such
description.  All documents filed by the Registrant  pursuant to Sections 13(a),
13(c),  14 and 15(d) of the  Exchange  Act  after the date of this  registration
statement and prior to the filing of a post-effective  amendment which indicates
that all securities  offered have been sold or which  deregisters all securities
then remaining  unsold,  shall be deemed to be incorporated by reference in this
registration  statement  and to be part  hereof  from  the date of  filing  such
documents.

ITEM 4. DESCRIPTION OF SECURITIES.

     Not applicable.

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL

     Not applicable.

ITEM 6. INDEMNIFICATION OF OFFICERS AND DIRECTORS

     The Company's  Restated  Articles of  Incorporation  limit,  to the maximum
extent  permitted  by Arizona law,  the  personal  liability  of  directors  for
monetary  damages  for  breach  of their  fiduciary  duties as a  director.  The
Company's  Restated  Articles of  Incorporation  provide that the Company  shall
indemnify  its officers and  directors to the fullest  extent  permitted by law,
subject to certain  exceptions.  The Company has  entered  into  indemnification
agreements with its officers and directors  containing  provisions  which are in
some respects broader than the specific indemnification  provisions contained in
the Arizona Revised  Statutes.  The  indemnification  agreements may require the
Company,  among other things,  to indemnify such officers and directors  against
certain  liabilities  that may  arise by reason of their  status or  service  as
directors or officers (other than liabilities arising from willful misconduct of
a  culpable  nature),  to advance  their  expenses  incurred  as a result of any
proceeding  against  them as to which they could be  indemnified,  and to obtain
directors'  and  officers'  insurance,  if available on  reasonable  terms.  The
Company  believes  that these  agreements  are  necessary  to attract and retain
qualified persons as directors and officers.

     At present,  there is no pending  litigation  or  proceeding  involving any
director,  officer,  employee or agent of the Company where indemnification will
be required or permitted.  The Company is not aware of any threatened litigation
or proceeding which may result in a claim or such indemnification.

     The  Company  currently   maintains   directors'  and  officers'  liability
insurance.

ITEM 8. EXHIBITS.

     Exhibit
     Number
     ------
     4.1       Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement
               Trust, as amended
     5.1       Opinion of John L. Gardner
     23.1      Consent of Independent Auditors
     23.2      Consent of Counsel (contained in Exhibit 5.1)
     25.1      Power of Attorney (included on the signature page to this
               Registration Statement)

ITEM 9. UNDERTAKINGS.

     (a)  The undersigned Registrant hereby undertakes:

          (1)  To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement:

               (i)  To include any prospectus required by Section 10(a)(3) of
the Securities Act of 1933;

               (ii) To reflect in the prospectus any facts or events arising
after the effective date of the registration statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represent a fundamental change in the information set forth in the registration
statement. Notwithstanding the foregoing, any increase or decrease in volume of
securities offered (if the total dollar value of securities offered would not
exceed that which was registered) and any deviation from the low or high end of
the estimated maximum offering range may be reflected in the form of prospectus
filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the
changes in volume and price represent no more than a 20% change in the maximum
aggregate offering price set forth in the "Calculation of Registration Fee"
table in the effective registration statement;

                                      -2-

               (iii) To include any material information with respect to the
plan of distribution not previously disclosed in the registration statement or
any material change to such information in the registration statement.

          PROVIDED, HOWEVER, that paragraphs (a)(1)(i) and (a)(1)(ii) of this
section do not apply if the registration statement is on Form S-3, Form S-8 or
Form F-3, and the information required to be included in a post-effective
amendment by those paragraphs is contained in periodic reports filed with or
furnished to the Commission by the Registrant pursuant to Section 13 or Section
15(d) of the Securities Exchange Act of 1934 that are incorporated by reference
in this registration statement.

          (2)  That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

          (3)  To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

     (b)  The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

     (c)  Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Registrant pursuant to the foregoing provisions, or otherwise,
the Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act of 1933 and will be governed by the final adjudication of such issue.

                                       -3-

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Tempe, State of Arizona, on this 30th day of June,
2003.

                                        INTER-TEL, INCORPORATED

                                        By: /s/ Kurt R. Kneip
                                            ------------------------------------
                                            Kurt R. Kneip

                                POWER OF ATTORNEY

     KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below hereby constitutes and appoints Kurt R. Kneip and John L. Gardner,
and each of them acting individually, as his or her attorney-in-fact, each with
full power of substitution, for him or her in any and all capacities, to sign
any and all amendments to this Registration Statement on Form S-8, and to file
the same, with exhibits thereto and other documents in connection therewith,
with the SEC, hereby ratifying and confirming all that each of said
attorneys-in-fact, or any substitute, may do or cause to be done by virtue
hereof.

     Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
dates indicated:

       SIGNATURE                        TITLE                          DATE
       ---------                        -----                          ----

 /s/ Steven G. Mihaylo     Chairman of the Board, President        June 30, 2003
-----------------------    and Chief Executive Officer
   Steven G. Mihaylo       (Principal Executive Officer)


    /s/ Norman Stout       Executive Vice President and            June 30, 2003
-----------------------    Chief Administrative Officer
      Norman Stout


  /s/ Craig W. Rauchle     Executive Vice President                June 30, 2003
-----------------------    and Chief Operating Officer
    Craig W. Rauchle


   /s/ Kurt R. Kneip       Chief Financial Officer                 June 30, 2003
-----------------------
     Kurt R. Kneip


 /s/ J. Robert Anderson    Director                                June 30, 2003
-----------------------
   J. Robert Anderson


  /s/ Jerry W. Chapman     Director                                June 30, 2003
-----------------------
    Jerry W. Chapman


     /s/ Gary Edens        Director                                June 30, 2003
-----------------------
       Gary Edens


  /s/ C. Roland Haden      Director                                June 30, 2003
-----------------------
    C. Roland Haden

     Pursuant to the requirements of the Securities Act, the trustees (or other
persons who administer the employee benefit plan) have duly caused this
registration statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Tempe, State of Arizona, on July 8, 2003

Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement Trust

By: /s/ Kurt R. Kneip
    ------------------------------
    Kurt R. Kneip
    Plan Administrator
    July 8, 2003

                                INDEX TO EXHIBITS

EXHIBIT
NUMBER                             DESCRIPTION
------                             -----------
4.1       Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement
          Trust, as amended
5.1       Opinion of John L. Gardner, General Counsel
23.1      Consent of Independent Auditors
23.2      Consent of Counsel (contained in Exhibit 5.1)
24.1      Power of Attorney (included on the signature page to this Registration
          Statement)