NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

SILVERLAKE prefixes in area code 425

NANPA records 17 assigned NXX blocks to rate center SILVERLAKE in area code 425, 2.7% of the 628 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 8 holders hold those blocks, the largest being ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER (6), ONVOY, LLC - WA (3), ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM (2). The earliest assignment on record here is 2002-02-28 and the most recent 2025-12-19. 14 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots. The same rate center name also appears in area codes 260, 262, 320, 458 – overlay codes cover the same geography, so a rate center is served by all of them.

17 assigned blocks – 2.7% of 425
8 holders of record
14 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
425-224 Allstream ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM – yes yes
425-225 Lumen LEVEL 3 TELECOM OF WASHINGTON, LLC - WA – yes yes
425-316 Ziply Fiber ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER – yes yes
425-321 Lumen LEVEL 3 COMMUNICATIONS, LLC - WA – yes yes
425-332 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
425-337 Ziply Fiber ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER – no yes
425-338 Ziply Fiber ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER – no yes
425-341 Allstream ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 2002-02-28 yes yes
425-357 Ziply Fiber ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER – yes yes
425-379 Ziply Fiber ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER – no yes
425-385 Ziply Fiber ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER – yes yes
425-399 Onvoy ONVOY, LLC - WA – yes yes
425-552 Onvoy ONVOY, LLC - WA 2022-09-01 yes yes
425-581 AT&T NEW CINGULAR WIRELESS PCS, LLC 2025-12-19 yes yes
425-585 WIDE VOICE, LLC - WA – yes yes
425-669 Onvoy ONVOY, LLC - WA – yes yes
425-948 Lumen LEVEL 3 COMMUNICATIONS, LLC - WA – yes yes

The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.

Who holds the blocks

HolderBrandBlocksShare here
ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER Ziply Fiber 6 35.3%
ONVOY, LLC - WA Onvoy 3 17.6%
ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM Allstream 2 11.8%
LEVEL 3 COMMUNICATIONS, LLC - WA Lumen 2 11.8%
LEVEL 3 TELECOM OF WASHINGTON, LLC - WA Lumen 1 5.9%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC Verizon 1 5.9%
NEW CINGULAR WIRELESS PCS, LLC AT&T 1 5.9%
WIDE VOICE, LLC - WA – 1 5.9%

Same rate center in other codes

Overlay codes cover the same geography, so one rate center is served by all of them.

Frequently asked

Which prefixes belong to SILVERLAKE in area code 425?

17 blocks: 224, 225, 316, 321, 332, 337, 338, 341, 357, 379, 385, 399 and 5 more, all listed in the table above.

Which carriers have numbers in SILVERLAKE?

ZIPLY FIBER NORTHWEST, LLC DBA ZIPLY FIBER (6 blocks), ONVOY, LLC - WA (3 blocks), ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM (2 blocks), LEVEL 3 COMMUNICATIONS, LLC - WA (2 blocks), LEVEL 3 TELECOM OF WASHINGTON, LLC - WA (1 block), MCIMETRO ACCESS TRANSMISSION SERVICES LLC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is SILVERLAKE a city?

It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.

Other rate centers in 425

All 628 prefixes in 425