206 Area Code: Seattle and the 564 Oddity

The 206 area code is Seattle and its immediate ring — the city proper, close-in suburbs like Shoreline, and Mercer, Bainbridge, and Vashon Islands. Since June 10, 2025, new lines in that footprint may instead draw area code 564, an overlay spanning all of western Washington.

That pairing is the strange part. Most overlays copy one code’s boundary exactly. 564 doesn’t — it was approved as a single relief code for four western Washington area codes at once, and Seattle is only its second stop. Here is how a code that once covered the entire state ended up sharing the city with an overlay bigger than some states.

From the whole state to one city

When the 1947 numbering plan was drawn, 206 was assigned to all of Washington. It has been shrinking ever since:

• 1957 — 509 split off the eastern two-thirds of the state, along a line roughly following the Cascades. 206 kept the populous west side.
• 1995 — 360 took western Washington outside the Seattle metro: Olympia, Bellingham, Vancouver, the peninsulas.
• April 27, 1997 — a three-way split cut the metro itself. Tacoma and the south went to 253; Everett and the Eastside (Bellevue, Redmond) went to 425. 206 kept Seattle.

Fifty years of splits reduced the statewide original to one city — which is exactly why a 206 number reads as unambiguously Seattle in a way few area codes match.

What 206 covers today

The modern footprint is compact: Seattle itself, near-in suburbs such as Shoreline and Lake Forest Park, communities running roughly from Des Moines north to Woodway — and three islands. Mercer Island sits in Lake Washington; Bainbridge and Vashon Islands sit across Puget Sound, closer by water to Seattle than by road to anything else, and both dial 206 rather than the surrounding 360 and 253.

So the code that once reached Spokane now stops at the city line and the ferry routes. Everything beyond — Tacoma, Bellevue, Everett, Olympia — answers on 253, 425, or 360.

564: the overlay that covers half a state

Here is the oddity. When Washington regulators planned relief in the late 1990s, NANPA issued planning letters for 564 first as a 360 overlay (1999), then expanded it to overlay 206, 253, 360, and 425 together (2000) — one new code stretched across all of western Washington. Number-conservation measures like prefix pooling then stretched the existing supply, and regulators suspended the whole project in 2001.

It finally launched on August 28, 2017 — but with a twist in the mechanics: 564 numbers were initially issued only in the 360 territory, even though the overlay legally spans all four codes. Mandatory ten-digit dialing arrived across western Washington that July to prepare.

Seattle’s turn came when 206 neared exhaustion. The Washington Utilities and Transportation Commission opened the 206 phase in June 2023, and since June 10, 2025, new numbers requested in the 206 area may be assigned 564 instead. 253 and 425 join only when they run low — the overlay activates region by region, as needed.

What a 564 number tells you (and doesn’t)

This is where 564 differs from a normal overlay. A 326 number is Dayton; a 332 number is Manhattan. A 564 number is somewhere in western Washington — Olympia, Bellingham, Vancouver, or, since mid-2025, Seattle. You can’t narrow it further from the code alone, only that the line is relatively new.

Contrast that with Delaware’s 302, a statewide code by geography, or Los Angeles’s 213, an original 1947 code pared down to a city core the way 206 was. 564 is the reverse construction: not a territory that shrank to fit, but a single spare tank plumbed into four territories at once.

Placing an unknown 206 or 564 caller

Context first: 206’s routine callers are Seattle’s — hospital systems like UW Medicine, the port and ferry ecosystem, and the tech-employer layer of recruiters, vendors, and startups. A 564 caller may be any of that, or a landscaper in Olympia.

Then the rule that outranks all geography: the displayed code proves nothing. Numbers follow their owners through ports, VoIP places calls from any network, and spoofing can forge 206 — or your own prefix — from anywhere on earth. Our area code guide explains why the code stopped being a trust signal. The habit that works: tell inbound callers nothing sensitive, hang up, and dial a number you look up on your own.

A Seattle number for your business

Because 206 still maps tightly to the city, it carries real local-presence weight — Seattle customers, and the tech companies that recruit and sell there, recognize it instantly. Local presence dialing works measurably better when the code actually matches the market, and 206 inventory still exists at the rate-center level even as new retail assignments spill into 564.

Businesses serving Puget Sound — including out-of-market teams that want a Seattle front door — can hold local DID numbers in 206 or 564, assigned at the rate-center level with no Seattle street address required, and deliver them to any PBX or softphone over SIP trunking.

Frequently asked questions

SIPNEX is an FCC-licensed carrier providing Seattle DIDs and local numbers across US area codes, toll-free numbers as a registered RespOrg, and high-volume SIP trunking — every call signed with our own STIR/SHAKEN certificate at A-level attestation. Talk to an operator at (833) 665-2220 or see rates.