WASHINGTON prefixes in area code 636
NANPA records 13 assigned NXX blocks to rate center WASHINGTON in area code 636, 3.0% of the 435 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. 9 holders hold those blocks, the largest being SOUTHWESTERN BELL (4), ONVOY, LLC - MO (2), PAETEC ITEL, LLC (1). The earliest assignment on record here is 2002-01-16 and the most recent 2025-09-19. 11 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 207, 252, 309, 319 – overlay codes cover the same geography, so a rate center is served by all of them.
Prefixes assigned here
| Prefix | Holder of record | Assigned | Pooled | In service |
|---|---|---|---|---|
| 636-221 | AT&T SOUTHWESTERN BELL | 2002-05-14 | yes | yes |
| 636-231 | Windstream PAETEC ITEL, LLC | – | yes | yes |
| 636-239 | AT&T SOUTHWESTERN BELL | – | no | yes |
| 636-241 | Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | 2022-08-03 | yes | yes |
| 636-266 | Lumen LEVEL 3 COMMUNICATIONS, LLC - MO | 2002-02-28 | yes | yes |
| 636-283 | AT&T TELEPORT COMMUNICATIONS AMERICA, LLC - MO | 2007-06-06 | yes | yes |
| 636-291 | AT&T NEW CINGULAR WIRELESS PCS, LLC - IL | 2025-09-19 | yes | yes |
| 636-369 | Onvoy ONVOY, LLC - MO | 2021-03-11 | yes | yes |
| 636-390 | AT&T SOUTHWESTERN BELL | – | no | yes |
| 636-392 | AURORA COMMUNICATIONS, INC. - MO | 2008-06-03 | yes | yes |
| 636-432 | AT&T SOUTHWESTERN BELL | 2006-01-10 | yes | yes |
| 636-667 | T-Mobile T-MOBILE USA, INC. | 2002-01-16 | yes | yes |
| 636-900 | Onvoy ONVOY, LLC - MO | 2015-10-14 | 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
| Holder | Brand | Blocks | Share here |
|---|---|---|---|
| SOUTHWESTERN BELL | AT&T | 4 | 30.8% |
| ONVOY, LLC - MO | Onvoy | 2 | 15.4% |
| PAETEC ITEL, LLC | Windstream | 1 | 7.7% |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | Verizon | 1 | 7.7% |
| LEVEL 3 COMMUNICATIONS, LLC - MO | Lumen | 1 | 7.7% |
| TELEPORT COMMUNICATIONS AMERICA, LLC - MO | AT&T | 1 | 7.7% |
| NEW CINGULAR WIRELESS PCS, LLC - IL | AT&T | 1 | 7.7% |
| AURORA COMMUNICATIONS, INC. - MO | – | 1 | 7.7% |
| T-MOBILE USA, INC. | T-Mobile | 1 | 7.7% |
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 WASHINGTON in area code 636?
13 blocks: 221, 231, 239, 241, 266, 283, 291, 369, 390, 392, 432, 667 and 1 more, all listed in the table above.
Which carriers have numbers in WASHINGTON?
SOUTHWESTERN BELL (4 blocks), ONVOY, LLC - MO (2 blocks), PAETEC ITEL, LLC (1 block), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO (1 block), LEVEL 3 COMMUNICATIONS, LLC - MO (1 block), TELEPORT COMMUNICATIONS AMERICA, LLC - MO (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.
Is WASHINGTON 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.