What is what area code is 564?

Area code 564 is an overlay area code that was established on August 28, 2017, as a relief measure for the 360 area code in the state of Washington, United States. It covers the same geographic area as the 360 area code, which includes western Washington excluding the Seattle metropolitan area. The 564 area code was implemented to ensure an adequate supply of telephone numbers as the demand for new numbers in the region increased. Callers within the area must dial the full ten-digit phone number, including the area code, even for local calls.