FORM 11-K

ANNUAL REPORT

PURSUANT TO SECTION 15(d)
OF THE SECURITIES EXCHANGE ACT OF 1934

Inter-Tel, Incorporated

Inter-Tel, Incorporated

INTER-TEL, INCORPORATED
TAX DEFERRED SAVINGS PLAN AND RETIREMENT TRUST

Financial Statements and Supplemental Schedule
December 31, 2004 and 2003

Table of Contents

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Participants and the Plan Administrator of the

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

We have audited the accompanying statements of net assets available for benefits of Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement Trust at December 31, 2004 and 2003, and the related statement of changes in net assets available for benefits for the year ended December 31, 2004. These financial statements are the responsibility of the Plan’s management. Our responsibility is to express an opinion on these financial statements based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the financial statements are free of material misstatements. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in all material respects, the net assets available for benefits of Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement Trust at December 31, 2004 and 2003, and the changes in net assets available for benefits for the year ended December 31, 2004 in conformity with U.S. generally accepted accounting principles.

Our audits were conducted for the purpose of forming an opinion on the basic financial statements taken as a whole. The supplemental schedule of assets (held at end of year) is presented for purposes of additional analysis and is not a required part of the basic financial statements, but is supplementary information required by the Department of Labor’s Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. This supplemental schedule is the responsibility of the Plan’s management, and has been subjected to the auditing procedures applied in the audit of the basic financial statements and, in our opinion, is fairly stated in all material respects in relation to the basic financial statements taken as a whole.

/s/ MAYER HOFFMAN MCCANN P.C.

May 20, 2005
Phoenix, Arizona

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INTER-TEL, INCORPORATED
TAX DEFERRED SAVINGS PLAN AND RETIREMENT TRUST

STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS

See accompanying notes to financial statements.

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INTER-TEL, INCORPORATED
TAX DEFERRED SAVINGS PLAN AND RETIREMENT TRUST

STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS

Year ended December 31, 2004

See accompanying notes to financial statements.

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INTER-TEL, INCORPORATED
TAX DEFERRED SAVINGS PLAN AND RETIREMENT TRUST

NOTES TO FINANCIAL STATEMENTS

     The following description of the Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement Trust (the “Plan”) provides only general information. Participants should refer to the Plan document for a more complete description of the Plan’s provisions.

     General - The Plan is a defined contribution plan covering all employees of Inter-Tel, Incorporated and its subsidiaries (the “Company”). The Plan is administered by the Company. Effective January 1, 2001, an employee becomes eligible to participate in the Plan subsequent to the pay period in which the employee completes one hour of service. The Plan was established on December 1, 1984 and is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”).

     Contributions - Each year, participants may contribute a percentage or dollar amount of their annual compensation to the Plan up to the annual IRS maximum through regular payroll deductions. Participants have the opportunity to change the previously elected percentage or dollar contributions each business day, to be effective at the next bi-weekly payroll period. Eligible participants receive a discretionary matching Company contribution. For 2004, the Company matched 50 percent of the participant’s basic contribution limited to six percent of the participant’s 2004 compensation. At the Company’s discretion, it may allocate a non-elective contribution at the end of each Plan year according to the terms of the Plan.

     Participant accounts - Each participant’s account is credited with the participant’s contributions, the Company’s contributions and an allocation of Plan earnings. Allocations are based on participant account balances. The benefit a participant is entitled to receive is the participant’s vested account balance. Participants may elect to have their accounts invested in mutual funds or common stock of the Company as offered by the Plan, or they may elect to have their accounts invested through individual self-directed brokerage accounts.

     Vesting - Participants immediately vest in their voluntary contributions plus actual earnings thereon and amounts rolled over from other plans into the Plan. Vesting in the Company’s matching contribution is based on years of service. The employer contribution portion of each participant account vests starting the first year of service at a graduated amount each year until completing the sixth year of service. After six years, the participant is 100 percent vested in the employer contribution account.

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     Forfeitures - Forfeited balances of terminated participants’ nonvested accounts are used to reduce future employer contributions. In 2004, forfeitures totaled $108,487 and are reflected as a reduction of employer contributions receivable and employer contributions at December 31, 2004 in the accompanying financial statements.

     Participant loans - Participants can borrow from their accounts a minimum of $1,000, up to a maximum equal to the lesser of $50,000 or 50% of their vested account balance. Loan terms range up to a maximum of five years, with the exception of loans for the purchase of a primary residence, which carry a maximum of up to twenty years. Loans are secured by the balance in the participant’s account and bear interest at a rate commensurate with prevailing rates at the time the loan is made as determined by the loan administrator. Principal and interest is generally paid ratably through payroll deductions.

     Payment of benefits - Upon termination of service, a participant may receive a lump-sum amount equal to the vested value of his or her account. Upon death, disability, or retirement, participants or their beneficiaries may elect to receive lump sums or annual installments over a 10 year period.

     Plan termination - Although the Company intends to continue the Plan indefinitely for the benefit of its participants, the Company has the right to discontinue its contributions at any time and to terminate or modify the Plan, subject to the provisions of ERISA. In the event of termination of the Plan, participants will become 100 percent vested in all of their accounts.

     The significant accounting policies followed by the Plan are as follows:

     Investment valuation and income recognition - The Plan’s investments are stated at fair value. Securities and mutual funds traded on national securities exchanges are valued at the last quoted sales price on the principal exchange on which they are traded. Securities, limited partnerships and real estate promissory notes for which no price is readily available on the valuation date are valued at fair value as determined by the Plan Administrator. Participant loans are valued at their outstanding balances, which approximates fair value. Purchases and sales of securities are recorded on a trade date basis. Interest income is recorded on the accrual basis. Dividends are recorded on the ex-dividend date.

     Use of estimates - The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of net assets, and the reported amounts of changes in net assets during the year. Actual results could differ from those estimates.

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     Concentrations of credit and investment risk - The Plan provides for various investment fund options, which in turn invest in any combination of mutual funds and other investment securities. Investment securities are exposed to various risks, such as interest rate, credit and overall market volatility risks. Due to the level of risk associated with certain investment securities, it is reasonably possible that changes in risks in the near term could materially affect participants’ account balances and the amounts reported in the statements of net assets available for benefits and the statement of changes in net assets available for benefits.

     During 2004, the Plan’s investments (including gains and losses on investments bought and sold, as well as held during the year) appreciated in fair value as follows:

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     Investments that represent five percent or more of the Plan’s net assets at December 31 are as follows:

     Substantially all of the Plan’s administrative expenses, except for record-keeper fees associated with several specific fund expenses and special transaction fees, are paid by the Company.

     The following is a reconciliation of items reported in these financial statements to the amounts reported in Form 5500 for (1) contributions of participants, (2) interest and dividend income, and (3) corrective distributions:

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     Certain plan investments are shares of common stock of the Company or are funds held and managed by Charles Schwab Trust Company, the asset custodian; accordingly, these transactions qualify as party-in-interest transactions. Such transactions, while considered party-in-interest transactions under ERISA regulations, are permitted under the provisions of the Plan and are specifically exempt from the prohibition of party-in-interest transaction under ERISA. Fees paid and accrued by the Plan to the record-keeper for administrative fees amounted to $61,347 for the year ended December 31, 2004.

     The Plan has received a favorable determination letter from the Internal Revenue Service dated February 11, 2004 stating that the Plan is qualified under Section 401(a) of the Internal Revenue Code (‘’the Code”) and, therefore, that the related trust is exempt from federal and state income or franchise taxation. Once qualified, the Plan is required to operate in conformity with the Code to maintain its qualification. The Plan administrator believes the Plan is being operated in compliance with the applicable requirements of the Code and ERISA, and, therefore, believes that the Plan is qualified and the related trust is exempt from federal and state income or franchise taxes.

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SCHEDULE H, LINE 4(i)
SCHEDULE OF ASSETS (HELD AT END OF YEAR)
DECEMBER 31, 2004

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Inter-Tel, Incorporated Tax Deferred Savings Plan and Retirement Trust has duly caused this report to be signed by the undersigned hereunto duly authorized.

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

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EXHIBIT INDEX

Exhibit:

     Exhibit 23.1 — Consent of Independent Registered Public Accounting Firm

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