The new year will also bring a new area code to Western Washington, our online news partner The Seattle Times reports.
Wireless carrier T-Mobile has begun warning its customers in area codes 360, 425, 253 and 206 about the addition of area code 564.
According to the T-Mobile website, all of Western Washington will be affected. The 564 area code overlay will be introduced initially in the existing 360 area code region, and then expanded to the 206, 253, and 425 area codes when those numbers run out.
T-Mobile said in its notice to customers that new numbers may be assigned the 564 area code beginning on Aug. 28.
The North American Numbering Plan Administrator projects the 360 area code will be out of numbers by early 2018, according to the Utilities and Transportation Commission, which approved the new area code earlier this year, the Times said.
To complete local calls in western Washington, the new dialing procedure requires callers to dial the area code plus the seven-digit telephone number. “This means that all calls in the 206, 253, 360, and 425 area codes that are currently dialed with 7 digits will need to be dialed using 10 digits,” T-Mobile said.
The same dialing procedure will apply to telephone numbers assigned from the new 564 area code. Calls that are currently local will continue to be local, even though 10-digit dialing will be required.