UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

_______________________________

SCHEDULE 13D

under the Securities Exchange Act of 1934
(Amendment No. 18)*

Inter-Tel (Delaware), Incorporated

(Name of Issuer)

Common Stock

(Title of Class of Securities)

458372109

(CUSIP Number)

Steven G. Mihaylo

P.O. Box 19790

Reno, Nevada 89511

(775) 338-4699

(Name, Address and Telephone Number of Person Authorized to
Receive Notices and Communications)

Copies to:

Brian J. McCarthy, Esq.

Skadden, Arps, Slate, Meagher & Flom LLP

300 South Grand Avenue

Los Angeles, California 90071

(213) 687-5000

June 26, 2007

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box [ ].

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP NO. 458372 109

1.	Names of Reporting Persons. Steven G. Mihaylo I.R.S. Identification Nos. of above persons (entities only). Not applicable.
2.	Check the Appropriate Box if a Member of a Group (see Instructions)
	(A) (B)		[ ] [ ]
3.	SEC Use Only
4.	Source of Funds (see Instructions) OO, BK
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e) [__]
6.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With		7.		Sole Voting Power 5,189,748
		8.		Shared Voting Power None
		9.		Sole Dispositive Power 5,189,748
		10.		Shared Dispositive Power None
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 5,189,748
12.	Check if the Aggregate Amount In Row (11) Excludes Certain Shares (See Instructions) [__]
13.	Percent of Class Represented by Amount in Row 11 19.0%
14.	Type Of Reporting Person (See Instructions) IN

This Amendment No. 18 (“Amendment No. 18”) amends and supplements the Schedule 13D, dated March 3, 2006 (the “Original Schedule 13D”), and filed by Steven G. Mihaylo (“Mr. Mihaylo”) with the Securities and Exchange Commission (the “SEC”) on March 6, 2006, as amended by Amendment No. 1 thereto, dated April 10, 2006 and filed by Mr. Mihaylo with the SEC on April 10, 2006 (“Amendment No. 1”), Amendment No. 2 thereto, dated April 21, 2006 and filed by Mr. Mihaylo with the SEC on April 21, 2006 (“Amendment No. 2”), Amendment No. 3 thereto, dated May 8, 2006 and filed by Mr. Mihaylo with the SEC on May 8, 2006 (“Amendment No. 3”), Amendment No. 4 thereto, dated May 18, 2006 and jointly filed by Mr. Mihaylo and Vector Capital Corporation (“Vector”) with the SEC on May 18, 2006 (“Amendment No. 4”), Amendment No. 5 thereto, dated June 15, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on June 15, 2006 (“Amendment No. 5”), Amendment No. 6 thereto, dated June 29, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on June 29, 2006 (“Amendment No. 6”), Amendment No. 7 thereto, dated July 28, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on July 28, 2006 (“Amendment No. 7”), Amendment No. 8 thereto, dated August 21, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on August 21, 2006 (“Amendment No. 8”), Amendment No. 9 thereto, dated August 22, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on August 23, 2006 (“Amendment No. 9”), Amendment No. 10 thereto, dated August 25, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on August 25, 2006 (“Amendment No. 10”), Amendment No. 11 thereto, dated October 24, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on October 25, 2006 (“Amendment No. 11”), Amendment No. 12 thereto, dated November 8, 2006 and jointly filed by Mr. Mihaylo and Vector with the SEC on November 9, 2006 (“Amendment No. 12”), Amendment No. 13 thereto, dated March 2, 2007 and jointly filed by Mr. Mihaylo and Vector with the SEC on March 6, 2007 (“Amendment No. 13”), Amendment No. 14 thereto, dated March 30, 2007 and filed by Mr. Mihaylo with the SEC on April 2, 2007 (“Amendment No. 14”), Amendment No. 15 thereto, dated June 4, 2007 and filed by Mr. Mihaylo with the SEC on June 5, 2007 (“Amendment No. 15”), Amendment No. 16 thereto, dated June 4, 2007 and filed by Mr. Mihaylo with the SEC on June 6, 2007 (“Amendment No. 16”), and Amendment No. 17 thereto, dated June 8, 2007 and filed by Mr. MIhaylo with the SEC on June 11, 2007 (“Amendment No. 17”, and, collectively with the Original Schedule 13D, Amendment No. 1, Amendment No. 2, Amendment No. 3, Amendment No. 4, Amendment No. 5, Amendment No. 6, Amendment No. 7, Amendment No. 8, Amendment No. 9, Amendment No. 10, Amendment No. 11, Amendment No. 12, Amendment No. 13, Amendment No. 14, Amendment No. 15 and Amendment No. 16, the “Schedule 13D”), with respect to the common stock, par value $0.001 per share (“Common Stock”), of Inter-Tel (Delaware), Incorporated, a Delaware corporation (“Inter-Tel” or the “Company”), formerly known as Inter-Tel, Incorporated, an Arizona corporation. Capitalized terms used but not defined herein shall have the respective meanings set forth in the Schedule 13D.

Item 4.

Purpose of Transaction.

The response to Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following paragraphs at the end of such Item 4:

Written Demand for Appraisal of Shares

On June 26, 2007, prior to the taking of the vote on the Merger, Mr. Mihaylo sent a written demand for appraisal of the 1,498 shares of Common Stock held of record by Mr. Mihaylo. Also on June 26, 2007, prior to the taking of the vote on the Merger, the Trust sent a written demand for appraisal of the 5,178,000 shares of Common Stock held of record by the Trust, and of which Mr. Mihaylo is the beneficial owner.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated:

June 27, 2007

		/s/ Steven G. Mihaylo
	STEVEN G. MIHAYLO

INTER TEL (DELAWARE), INC SC 13D/A