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Archived Area Code News

Flint, Ann Arbor, and Dearborn to Receive Additional Area Codes

The state of Michigan has received its first area code "overlay" affecting the Flint area, including the University of Michigan at Flint. A new area code, 586, was added to the current 810 area code on February 5, 2000.

An area code "overlay" is a second area code that is added to a geographic area along with an existing area code. All existing numbers retain their current area code, while new telephone customers for local phone service, cellular and paging services, and alarms may be assigned a telephone number in the new overlay area code. The Federal Communications Center (FCC) has authorized the use of area code overlays because many areas of the country have run out of valid telephone numbers within their existing area.

The most notable effect of the overlay plan is the requirement of dialing 11-digits for all calls, both local and long distance. The 11-digit numbers will require dialing 1+ area code + seven digit phone number. Callers who must dial "9" or another number to obtain an outside line will need to dial 12 numbers (9 + 1 + area code + seven digit phone number) for local and long distance calls. All calls assigned the new area code will be affected by this new dialing pattern--including manually dialed numbers as well as programmable faxes, modems, and phones.

An "optional dialing period" will be offered prior to full implementation of the new Flint area code. Until March 6, 2000, customers will have an opportunity to become familiar with the new 11-digit dialing pattern during the transition. They will also be able to dial seven digits for a local call during this time period.

On July 8, 2000, Ann Arbor will acquire overlay area code 278 in addition to the current 734 area code. The optional dialing period for Ann Arbor will end November 4, 2000. Dearborn will acquire an overlay area code, 679, on November 4, 2000 with an optional dialing period that ends on February 3, 2001.

Note: the price of telephone calls will not be affected by the new overlay area codes. On campus five-digit dialing will not be impacted at this time.

New Michigan Area Code (A.C.) Overlays
City Current A.C. New Overlay Optional dialing begins Optional dialing ends
Ann Arbor 734 278 July 8, 2000 November 4, 2000
Dearborn 313 679 November 4, 2000 February 3,2001
Flint 810 586 February 5, 2000 May 6, 2000

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Area Code Overlay Delays

Implementation of Flint Area Code Overlay Delayed (5/1/00)

The implementation plan for the 810 area code overlay has been delayed by the Federal Communications Commission (FCC). On February 5, the Flint area (including the U-M Flint campus) received an additional area code: 586. Mandatory dialing of the new area code was scheduled to begin May 6.

The implementation delay was caused by questions raised by the FCC over the authority of the North American Numbering Plan Administrator (NANPA) and the Michigan telecommunications industry to implement relief for the 810 area code. It is anticipated that the FCC will request public comment for the proposed 810/586 overlay plan before approving it. No date has been announced for the FCC decision.

Despite the temporary delay in the 810/586 overlay implementation, no delays have been announced for either of two other overlay implementation plans:

  • ANN ARBOR AREA: A new area code, 278, will overlay the existing 734 area code. This is scheduled to begin July 8 and become mandatory on November 4.
  • DEARBORN AREA: A new area code, 679, will overlay the existing 313 area code. This is scheduled to begin November 4 and become mandatory on February 3, 2001.

An area code overlay increases the available telephone numbers by adding a new area code so two area codes then co-exist in the same geographic area. As a result, seven-digit dialing is no longer possible within the affected area. Callers must dial "1" plus the area code plus the seven-digit phone number for all calls -- whether local or long distance -- including calls within the same area code.

Area Code Overlays Postponed for Ann Arbor and Dearborn (5/19/00)

The implementation of the new area code overlays scheduled by Ameritech for Ann Arbor and Dearborn has been postponed by the Federal Communications Commission (FCC). The delay in the 734/278 area code overlay for Ann Arbor, and the 313/679 area code overlay for Dearborn follows a similar delay for Flint's 810/586 area code overlay plan, which was announced in the May 8 issue of The University Record.

Please call ITCom Customer Services at 763-2000 if you have questions or concerns about the overlay issue.