Washington Utilities and Transportation Commission issued a reminder today that all telephone calls dialed west of the Cascades starting this weekend must include an area code.

UTC regulators approved a new area code for western Washington in May 2016, because telecommunications providers are running out of new phone numbers to issue.

The new area code – 564 – will overlay the entire west half of the state and initially be used in the 360 area code territory. As more numbers are needed in 253, 206 and 425 area codes, they too will be given the 564 prefix.

Beginning this Saturday, if calls made within western Washington only seven digits without an area code, the calls will not be completed. The caller will hear an announcement instructing them to redial including the area code.

All customers should confirm that services, automatic dialing equipment, applications, software, or other types of equipment recognize the new 564 area code. This may include life-safety systems, fax machines, internet dial-up numbers, alarm and security systems, gates, ankle monitors, speed dialers, mobile phone contact lists, call forwarding settings, voicemail services, and similar functions.

For more information, please visit the UTC’s website at www.utc.wa.gov or contact your local telephone service provider.