– From the Washington Utilities and Transportation Commission, July 25, 2017
“Mandatory 10-digit dialing for western Washington begins this week”
Callers in western Washington will have to dial the area code along with the seven-digit telephone number to make a local call beginning Saturday, July 29.
Mandatory 10-digit dialing to accommodate the new 564 area code overlay for western Washington.
Washington Utilities and Transportation Commission
WHEN and WHERE
Saturday, July 29
The Washington Utilities and Transportation Commission approved a new area code for western Washington in May 2016 to address the need for additional numbers. To implement the new area code, the commission also approved mandatory 10-digit dialing for all of western Washington.
The new area code, 564, will overlay all of Western Washington and initially be distributed to the 360 area code territory. As numbers are needed in the 206, 253 and 425 area code territories, 564 will be distributed to meet the demand.
Beginning July 29, all calls made within western Washington must be placed using the 10 digit telephone number. If consumers dial only seven digits, the call will not be completed and the caller will hear an announcement instructing them to redial including the area code.
The 564 area code will be assigned to new telephone lines or services beginning August 28.