Get ready to see more 564s in Washington.

T-Mobile is notifying customers that the new area code will be rolling out in Western Washington state starting July 29.

The new area code was approved in 2000 and will eventually expand to Seattle (206), Tacoma (253), and Bellevue and Redmond (425) when those regions run out of number combinations.

Washington state is seeing rapid population growth, particularly in King, Snohomish, and Pierce counties. The new area code will help deal with the influx of newcomers seeking local phone numbers.