The Utilities and Transportation Commission this week approved a plan to implement a new area code across western Washington to address the need for additional numbers.

The new area code, 564, will be available to all of western Washington including the 360, 206, 253, and 425 area codes as numbers in those areas become exhausted.

To implement the new area code, the commission also approved mandatory 10-digit dialing for all western Washington area codes by the fall of 2017. This will require callers to dial all 10 digits of a telephone number, including area code, when making local calls.

The North American Numbering Plan Administrator projects the 360 area code will be out of numbers by early 2018. The 564 area code will start being distributed in the fall of 2017 to new numbers in the 360 area code.

As part of the plan, western Washington telephone service providers must implement a comprehensive education program to inform customers of the new dialing requirement. This includes customer education, community involvement, and media outreach.

The commission originally approved the single area code overlay for western Washington in 2000, but postponed it after successful state and national number conservation efforts.

The UTC regulates the rates and services of telecommunications companies, investor-owned electric utilities, natural gas and water companies, garbage-collection haulers, household-goods movers and charter-bus companies, commercial ferries, pipeline companies, and a low-level radioactive waste repository.