Area code 403

Its numbering plan area (NPA) originally comprised the entire province of Alberta.

[1] Within only a year, area code 403 was threatened by exhaustion because of the rapid growth of telecommunication services demand for pagers, cellphones, and computer modems, as well as growing competition among providers.

On January 25, 1999, the northern two thirds of Alberta, including Edmonton, was split from 403 and assigned the new area code 780.

[6] On September 20, 2008, Telus Mobility began to assign 587 telephone numbers to new customers in Calgary and Edmonton.

Prior to 1997, the larger 403 included EdTel (Edmonton Telephones, now part of Telus) and Northwestel as ILECs.