Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records
Area code 831 prefixes
406 of the 786 possible NXX blocks are assigned in area code 831 (51.7% of capacity), spread across 24 rate centers and 45 holders. The largest holders are PACIFIC BELL (124 blocks, 30.5%), NEW CINGULAR WIRELESS PCS, LLC (35 blocks, 8.6%), ONVOY, LLC - CA (31 blocks, 7.6%). Grouped by brand, AT&T accounts for 174 blocks; brand-attributable holders cover 86% of the code, and the rest are CLECs, VoIP wholesalers and regional carriers that trade under their own names. The assignment records here run from 2001-03-09 to 2026-09-03, with 13 blocks handed out in 2001 alone. 308 blocks (76%) are in thousands-block pooling, meaning the block is shared between carriers in 1,000-number lots rather than held whole – which is why a single NXX can serve several carriers at once. 2 assigned blocks (343, 365) are not yet in service: assigned to a carrier but not open for calls, so a caller ID from one is spoofed. 53 were growth assignments – additional blocks to a carrier that had already filled its earlier ones.
406 assigned blocks of 786
24 rate centers
45 holders of record
76% in thousands-block pooling
Largest holders in 831
| Holder of record, as NANPA names it | Brand | Blocks | Share |
|---|---|---|---|
| PACIFIC BELL | AT&T | 124 | 30.5% |
| NEW CINGULAR WIRELESS PCS, LLC | AT&T | 35 | 8.6% |
| ONVOY, LLC - CA | Onvoy | 31 | 7.6% |
| CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | Verizon | 30 | 7.4% |
| LEVEL 3 COMMUNICATIONS, LLC - CA | Lumen | 26 | 6.4% |
| IP HORIZON LLC | – | 14 | 3.4% |
| T-MOBILE USA, INC. | T-Mobile | 13 | 3.2% |
| METROPCS, INC. | T-Mobile | 13 | 3.2% |
| U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | TPx | 11 | 2.7% |
| BANDWIDTH.COM CLEC, LLC - CA | Bandwidth | 11 | 2.7% |
| FRACTEL, LLC | – | 10 | 2.5% |
| PEERLESS NETWORK OF CALIFORNIA, LLC - CA | Peerless | 8 | 2% |
Names are printed as they appear in the assignment records, which is the legal entity rather than the brand. Holding a block is not the same as serving the numbers in it: portability moves numbers between carriers and pooling splits a block between several.
Rate centers with their own page
Rate centers where at least three blocks are assigned, excluding the numbered metro zone codes. The remainder are in the full table below.
All 406 assigned blocks
One row per NXX. “Pooled” means carriers draw 1,000-number lots from the block rather than holding all 10,000, so a pooled prefix can belong to several carriers at once. “Not in service” means assigned but not yet open for calls – a caller ID from one of those is necessarily spoofed. The holder column gives the brand where the legal entity maps to one; the full legal names are in the holders table above, exactly as NANPA records them.
| Prefix | Holder of record | Rate center | Assigned | Pooled | In service |
|---|---|---|---|---|---|
| 831-200 | Peerless | MONTEREY | 2014-11-26 | yes | yes |
| 831-201 | AT&T | SANTA CRUZ | 2016-09-07 | yes | yes |
| 831-202 | Verizon | SALINAS | 2018-03-30 | yes | yes |
| 831-203 | NUSO, LLC | SALINAS | 2023-08-10 | yes | yes |
| 831-204 | Onvoy | MONTEREY | – | yes | yes |
| 831-205 | AT&T | HOLLISTER | 2009-10-08 | yes | yes |
| 831-206 | Verizon | SALINAS | – | – | yes |
| 831-207 | T-Mobile | HOLLISTER | 2001-09-12 | yes | yes |
| 831-208 | Verizon | SALINAS | 2019-03-20 | yes | yes |
| 831-210 | T-Mobile | SALINAS | 2002-01-16 | yes | yes |
| 831-212 | T-Mobile | SANTA CRUZ | – | yes | yes |
| 831-214 | AT&T | SALINAS | – | – | yes |
| 831-215 | HD CARRIER LLC | MONTEREY | 2020-10-02 | yes | yes |
| 831-216 | AT&T | FELTON | – | yes | yes |
| 831-217 | AT&T | BOULDERCRK | – | yes | yes |
| 831-218 | AT&T | BEN LOMOND | – | yes | yes |
| 831-219 | AT&T | APTOS | – | yes | yes |
| 831-220 | Vonage | MONTEREY | 2018-05-31 | yes | yes |
| 831-221 | IP HORIZON LLC | SAN ARDO | – | yes | yes |
| 831-222 | TPx | FELTON | – | yes | yes |
| 831-223 | Lumen | SOLEDAD | – | yes | yes |
| 831-224 | T-Mobile | MONTEREY | – | yes | yes |
| 831-225 | Lumen | SALINAS | 2015-06-23 | yes | yes |
| 831-226 | AT&T | SANTA CRUZ | 2015-07-16 | yes | yes |
| 831-227 | Verizon | SANTA CRUZ | – | yes | yes |
| 831-228 | Charter | WATSONVL | 2015-09-21 | yes | yes |
| 831-229 | AT&T | SALINAS | – | – | yes |
| 831-230 | Telnyx | MONTEREY | 2016-12-15 | yes | yes |
| 831-231 | Charter | GREENFIELD | 2019-05-03 | yes | yes |
| 831-232 | IP HORIZON LLC | CHUALAR | – | yes | yes |
| 831-233 | Lumen | MONTEREY | – | yes | yes |
| 831-234 | Verizon | SANTA CRUZ | – | – | yes |
| 831-235 | Verizon | SALINAS | – | – | yes |
| 831-236 | Verizon | MONTEREY | – | – | yes |
| 831-237 | IP HORIZON LLC | SOLEDAD | – | yes | yes |
| 831-238 | AT&T | CARMEL | – | yes | yes |
| 831-239 | AT&T | SANTA CRUZ | – | – | yes |
| 831-240 | T-Mobile | SALINAS | – | yes | yes |
| 831-241 | AT&T | MONTEREY | – | yes | yes |
| 831-242 | AT&T | MONTEREY | – | yes | yes |
| 831-243 | CSC WIRELESS, LLC | SALINAS | 2020-06-29 | yes | yes |
| 831-244 | Bandwidth | BIG SUR | – | yes | yes |
| 831-245 | Verizon | HOLLISTER | – | yes | yes |
| 831-246 | Verizon | BEN LOMOND | – | yes | yes |
| 831-247 | Verizon | SANTA CRUZ | – | – | yes |
| 831-249 | AT&T | BIG SUR | 2009-12-14 | yes | yes |
| 831-250 | IP HORIZON LLC | CARMEL | – | yes | yes |
| 831-251 | AT&T | APTOS | – | – | yes |
| 831-252 | AT&T | BEN LOMOND | – | – | yes |
| 831-253 | TPx | SALINAS | 2020-12-04 | yes | yes |
| 831-254 | AT&T | WATSONVL | – | – | yes |
| 831-255 | NORTH COUNTY COMMUNICATION CORPORATION - CA | SANTA CRUZ | – | – | yes |
| 831-256 | Verizon | SALINAS | 2015-04-10 | yes | yes |
| 831-257 | Onvoy | APTOS | 2016-10-07 | yes | yes |
| 831-258 | AT&T | SALINAS | 2016-07-08 | yes | yes |
| 831-259 | TPx | MONTEREY | 2022-06-10 | yes | yes |
| 831-260 | AT&T | SOLEDAD | 2022-03-15 | yes | yes |
| 831-261 | AT&T | SALINAS | – | – | yes |
| 831-262 | Verizon | SALINAS | – | – | yes |
| 831-263 | IP HORIZON LLC | KING CITY | – | yes | yes |
| 831-264 | Bandwidth | MONTEREY | – | yes | yes |
| 831-265 | AT&T | HOLLISTER | 2008-04-02 | yes | yes |
| 831-266 | T-Mobile | SANTA CRUZ | 2021-03-24 | yes | yes |
| 831-267 | TPx | BIG SUR | 2006-12-14 | yes | yes |
| 831-268 | Onvoy | FELTON | 2016-07-15 | yes | yes |
| 831-269 | AT&T | SALINAS | 2007-06-21 | yes | yes |
| 831-270 | TPx | SALINAS | 2022-06-10 | yes | yes |
| 831-271 | Telnyx | HOLLISTER | 2021-06-23 | yes | yes |
| 831-272 | Onvoy | SALINAS | – | yes | yes |
| 831-273 | Onvoy | SALINAS | 2017-04-06 | yes | yes |
| 831-274 | Lumen | WATSONVL | – | yes | yes |
| 831-275 | Bandwidth | MONTEREY | 2008-10-23 | yes | yes |
| 831-276 | Telnyx | SALINAS | – | yes | yes |
| 831-277 | Verizon | MONTEREY | – | – | yes |
| 831-278 | Verizon | BEN LOMOND | – | yes | yes |
| 831-279 | Dish | SALINAS | 2023-05-10 | yes | yes |
| 831-280 | COMMIO, LLC | APTOS | 2023-08-11 | yes | yes |
| 831-281 | Verizon | SANTA CRUZ | 2023-10-02 | yes | yes |
| 831-282 | IP HORIZON LLC | MONTEREY | 2021-09-17 | yes | yes |
| 831-283 | COMMIO, LLC | CARMEL VLY | 2022-11-04 | yes | yes |
| 831-284 | AT&T | WATSONVL | 2023-08-28 | yes | yes |
| 831-285 | Bandwidth | WATSONVL | 2022-10-28 | yes | yes |
| 831-286 | Onvoy | GREENFIELD | 2024-03-21 | yes | yes |
| 831-287 | Bandwidth | SALINAS | 2008-12-16 | yes | yes |
| 831-288 | Charter | WATSONVL | 2009-06-11 | yes | yes |
| 831-289 | Comcast | BEN LOMOND | 2022-09-20 | yes | yes |
| 831-290 | TPx | GONZALES | 2009-06-26 | yes | yes |
| 831-291 | Verizon | SANTA CRUZ | 2014-04-07 | yes | yes |
| 831-292 | AT&T | SOLEDAD | 2019-01-08 | yes | yes |
| 831-293 | Lumen | CARMEL | 2008-06-25 | yes | yes |
| 831-294 | AT&T | SALINAS | 2024-03-25 | yes | yes |
| 831-295 | T-Mobile | SANTA CRUZ | 2001-12-14 | yes | yes |
| 831-296 | Lumen | SALINAS | 2010-07-12 | yes | yes |
| 831-297 | T-Mobile | HOLLISTER | 2001-12-14 | yes | yes |
| 831-298 | Onvoy | CARMEL VLY | – | yes | yes |
| 831-299 | Lumen | TRES PINOS | – | yes | yes |
| 831-300 | Lumen | BIG SUR | – | yes | yes |
| 831-301 | Peerless | SAN JUAN | – | yes | yes |
| 831-302 | Lumen | SAN LUCAS | – | yes | yes |
| 831-303 | Peerless | SAN ARDO | – | yes | yes |
| 831-304 | Peerless | GREENFIELD | – | yes | yes |
| 831-305 | Lumen | GONZALES | – | yes | yes |
| 831-306 | Lumen | CHUALAR | – | yes | yes |
| 831-307 | Lumen | CASTROVL | – | yes | yes |
| 831-308 | Bandwidth | CARMEL VLY | – | yes | yes |
| 831-309 | Bandwidth | CARMEL | 2017-05-08 | yes | yes |
| 831-312 | CSC VOICE, LLC | MONTEREY | 2024-03-26 | yes | yes |
| 831-313 | Charter | HOLLISTER | 2009-06-11 | yes | yes |
| 831-314 | SHELCOMM | SANTA CRUZ | 2024-09-12 | – | yes |
| 831-315 | Peerless | SOLEDAD | 2016-02-15 | yes | yes |
| 831-316 | Verizon | SANTA CRUZ | – | yes | yes |
| 831-317 | LEAP TELECOM, LLC | MONTEREY | 2024-09-23 | yes | yes |
| 831-318 | Onvoy | APTOS | 2016-03-17 | yes | yes |
| 831-319 | Verizon | WATSONVL | 2001-04-17 | yes | yes |
| 831-320 | Verizon | SALINAS | – | – | yes |
| 831-321 | AT&T | SALINAS | 2024-12-06 | yes | yes |
| 831-322 | Onvoy | WATSONVL | 2016-03-17 | yes | yes |
| 831-324 | Comcast | MONTEREY | – | yes | yes |
| 831-325 | T-Mobile | SANTA CRUZ | 2001-04-25 | yes | yes |
| 831-326 | AT&T | SALINAS | 2024-12-06 | yes | yes |
| 831-327 | AT&T | HOLLISTER | 2024-12-30 | yes | yes |
| 831-328 | Onvoy | SALINAS | 2025-03-13 | yes | yes |
| 831-329 | NUSO, LLC | SALINAS | 2025-04-21 | yes | yes |
| 831-330 | Charter | CARMEL | 2023-12-06 | yes | yes |
| 831-331 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-332 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-333 | AT&T | MONTEREY | – | yes | yes |
| 831-334 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-335 | AT&T | FELTON | – | – | yes |
| 831-336 | AT&T | BEN LOMOND | – | yes | yes |
| 831-337 | Verizon | BOULDERCRK | – | yes | yes |
| 831-338 | AT&T | BOULDERCRK | – | yes | yes |
| 831-339 | AT&T | GONZALES | 2025-09-04 | yes | yes |
| 831-340 | Verizon | SANTA CRUZ | 2026-01-15 | yes | yes |
| 831-343 | Onvoy | SALINAS | 2026-09-03 | yes | no |
| 831-345 | Verizon | SANTA CRUZ | 2001-11-13 | – | yes |
| 831-346 | T-Mobile | SANTA CRUZ | 2014-09-23 | yes | yes |
| 831-348 | FRACTEL, LLC | WATSONVL | 2019-03-20 | yes | yes |
| 831-350 | Lumen | TRES PINOS | 2006-05-11 | yes | yes |
| 831-353 | Onvoy | WATSONVL | 2016-07-18 | yes | yes |
| 831-356 | FRACTEL, LLC | SALINAS | 2019-12-02 | yes | yes |
| 831-359 | Lumen | SANTA CRUZ | – | yes | yes |
| 831-365 | Onvoy | SANTA CRUZ | 2026-07-24 | yes | no |
| 831-366 | TON80 COMMUNICATIONS, LLC | BOULDERCRK | 2022-02-23 | yes | yes |
| 831-372 | AT&T | MONTEREY | – | – | yes |
| 831-373 | AT&T | MONTEREY | – | – | yes |
| 831-375 | AT&T | MONTEREY | – | – | yes |
| 831-382 | AT&T | SAN LUCAS | – | yes | yes |
| 831-383 | T-Mobile | MONTEREY | 2001-09-13 | yes | yes |
| 831-384 | AT&T | MONTEREY | – | – | yes |
| 831-385 | AT&T | KING CITY | – | – | yes |
| 831-386 | AT&T | KING CITY | – | yes | yes |
| 831-387 | Bandwidth | KING CITY | – | yes | yes |
| 831-388 | Onvoy | GREENFIELD | 2022-09-08 | yes | yes |
| 831-389 | PINNACLES TEL. CO. | PINNACLES | – | – | yes |
| 831-392 | AT&T | MONTEREY | – | yes | yes |
| 831-393 | AT&T | MONTEREY | – | yes | yes |
| 831-394 | AT&T | MONTEREY | – | – | yes |
| 831-400 | VoIP Innovations | SANTA CRUZ | – | yes | yes |
| 831-401 | Lumen | BEN LOMOND | – | yes | yes |
| 831-402 | AT&T | MONTEREY | 2001-11-13 | yes | yes |
| 831-406 | T-Mobile | WATSONVL | 2001-12-14 | yes | yes |
| 831-417 | Onvoy | SALINAS | – | yes | yes |
| 831-419 | AT&T | SANTA CRUZ | – | – | yes |
| 831-420 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-421 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-422 | AT&T | SALINAS | – | – | yes |
| 831-423 | AT&T | SANTA CRUZ | – | – | yes |
| 831-424 | AT&T | SALINAS | – | – | yes |
| 831-425 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-426 | AT&T | SANTA CRUZ | – | – | yes |
| 831-427 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-428 | T-Mobile | SANTA CRUZ | – | yes | yes |
| 831-429 | AT&T | SANTA CRUZ | – | – | yes |
| 831-430 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-431 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-432 | FRACTEL, LLC | BOULDERCRK | 2020-12-21 | yes | yes |
| 831-435 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-438 | AT&T | SANTA CRUZ | – | – | yes |
| 831-439 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-440 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-442 | AT&T | SALINAS | – | yes | yes |
| 831-443 | AT&T | SALINAS | – | – | yes |
| 831-444 | AT&T | SALINAS | – | yes | yes |
| 831-449 | AT&T | SALINAS | – | – | yes |
| 831-453 | AT&T | CASTROVL | 2011-01-25 | yes | yes |
| 831-454 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-455 | AT&T | SALINAS | – | yes | yes |
| 831-457 | AT&T | SANTA CRUZ | – | – | yes |
| 831-458 | AT&T | SANTA CRUZ | – | – | yes |
| 831-459 | AT&T | SANTA CRUZ | – | – | yes |
| 831-460 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-461 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-462 | AT&T | SANTA CRUZ | – | – | yes |
| 831-464 | AT&T | SANTA CRUZ | – | – | yes |
| 831-465 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-466 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-468 | EXIANT COMMUNICATIONS LLC | MONTEREY | 2026-03-30 | yes | yes |
| 831-469 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-471 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-475 | AT&T | SANTA CRUZ | – | – | yes |
| 831-476 | AT&T | SANTA CRUZ | – | – | yes |
| 831-477 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-479 | AT&T | SANTA CRUZ | – | – | yes |
| 831-480 | Onvoy | SANTA CRUZ | – | – | yes |
| 831-484 | AT&T | SALINAS | – | yes | yes |
| 831-498 | IP HORIZON LLC | WATSONVL | – | yes | yes |
| 831-500 | T-Mobile | SALINAS | – | yes | yes |
| 831-502 | AT&T | SANTA CRUZ | – | – | yes |
| 831-508 | IP HORIZON LLC | FELTON | – | yes | yes |
| 831-512 | T-Mobile | SALINAS | – | yes | yes |
| 831-515 | TPx | SANTA CRUZ | – | yes | yes |
| 831-521 | AT&T | MONTEREY | – | – | yes |
| 831-524 | AT&T | HOLLISTER | – | yes | yes |
| 831-525 | Lumen | KING CITY | – | yes | yes |
| 831-529 | FRACTEL, LLC | SANTA CRUZ | 2020-03-27 | yes | yes |
| 831-531 | Verizon | APTOS | – | yes | yes |
| 831-532 | Onvoy | BEN LOMOND | – | yes | yes |
| 831-533 | Verizon | BOULDERCRK | – | yes | yes |
| 831-534 | Verizon | FELTON | – | yes | yes |
| 831-535 | Verizon | SANTA CRUZ | – | yes | yes |
| 831-536 | Verizon | WATSONVL | – | yes | yes |
| 831-537 | Verizon | HOLLISTER | – | yes | yes |
| 831-539 | T-Mobile | WATSONVL | – | yes | yes |
| 831-540 | Verizon | SALINAS | – | yes | yes |
| 831-566 | Verizon | SANTA CRUZ | 2002-06-14 | – | yes |
| 831-572 | UTILITY TELECOM GROUP, LLC - CA | APTOS | – | yes | yes |
| 831-574 | TPx | CARMEL | – | yes | yes |
| 831-576 | Onvoy | SANTA CRUZ | – | yes | yes |
| 831-578 | AT&T | SALINAS | – | yes | yes |
| 831-580 | IP HORIZON LLC | GONZALES | – | yes | yes |
| 831-582 | AT&T | MONTEREY | – | yes | yes |
| 831-583 | AT&T | MONTEREY | – | yes | yes |
| 831-585 | T-Mobile | SALINAS | 2005-02-18 | yes | yes |
| 831-586 | IP HORIZON LLC | SAN JUAN | – | yes | yes |
| 831-587 | FRACTEL, LLC | WATSONVL | 2021-08-23 | yes | yes |
| 831-588 | Verizon | SANTA CRUZ | – | – | yes |
| 831-593 | Charter | SAN JUAN | – | yes | yes |
| 831-594 | AT&T | SALINAS | – | – | yes |
| 831-595 | AT&T | SALINAS | – | – | yes |
| 831-596 | AT&T | SALINAS | – | – | yes |
| 831-597 | Peerless | SALINAS | – | yes | yes |
| 831-600 | TPx | SANTA CRUZ | – | yes | yes |
| 831-601 | Verizon | MONTEREY | – | – | yes |
| 831-603 | Onvoy | APTOS | – | – | yes |
| 831-604 | Onvoy | BEN LOMOND | – | – | yes |
| 831-607 | IP HORIZON LLC | APTOS | – | yes | yes |
| 831-609 | Onvoy | BEN LOMOND | – | yes | yes |
| 831-610 | Onvoy | BOULDERCRK | – | yes | yes |
| 831-612 | Lumen | APTOS | – | yes | yes |
| 831-613 | Bandwidth | GREENFIELD | – | yes | yes |
| 831-618 | Onvoy | BOULDERCRK | – | – | yes |
| 831-620 | AT&T | CARMEL | – | yes | yes |
| 831-621 | Lumen | SANTA CRUZ | – | yes | yes |
| 831-622 | AT&T | CARMEL | – | – | yes |
| 831-623 | AT&T | SAN JUAN | – | yes | yes |
| 831-624 | AT&T | CARMEL | – | – | yes |
| 831-625 | AT&T | CARMEL | – | – | yes |
| 831-626 | AT&T | CARMEL | – | – | yes |
| 831-627 | AT&T | SAN ARDO | – | yes | yes |
| 831-628 | AT&T | TRES PINOS | – | yes | yes |
| 831-630 | AT&T | HOLLISTER | – | yes | yes |
| 831-632 | AT&T | CASTROVL | – | yes | yes |
| 831-633 | AT&T | CASTROVL | – | yes | yes |
| 831-634 | AT&T | HOLLISTER | – | yes | yes |
| 831-635 | AT&T | HOLLISTER | – | yes | yes |
| 831-636 | AT&T | HOLLISTER | – | – | yes |
| 831-637 | AT&T | HOLLISTER | – | – | yes |
| 831-638 | AT&T | HOLLISTER | – | – | yes |
| 831-641 | AT&T | MONTEREY | – | yes | yes |
| 831-642 | AT&T | MONTEREY | – | – | yes |
| 831-643 | AT&T | MONTEREY | – | yes | yes |
| 831-644 | AT&T | MONTEREY | – | – | yes |
| 831-645 | AT&T | MONTEREY | – | – | yes |
| 831-646 | AT&T | MONTEREY | – | – | yes |
| 831-647 | AT&T | MONTEREY | – | – | yes |
| 831-648 | AT&T | MONTEREY | – | – | yes |
| 831-649 | AT&T | MONTEREY | – | yes | yes |
| 831-652 | Lumen | CARMEL VLY | – | yes | yes |
| 831-653 | IP HORIZON LLC | SAN LUCAS | – | yes | yes |
| 831-655 | AT&T | MONTEREY | – | – | yes |
| 831-656 | AT&T | MONTEREY | – | yes | yes |
| 831-657 | AT&T | MONTEREY | – | yes | yes |
| 831-658 | AT&T | MONTEREY | – | – | yes |
| 831-659 | AT&T | CARMEL VLY | – | yes | yes |
| 831-661 | AT&T | APTOS | – | yes | yes |
| 831-662 | AT&T | APTOS | – | – | yes |
| 831-663 | AT&T | SALINAS | – | yes | yes |
| 831-664 | Lumen | HOLLISTER | – | yes | yes |
| 831-665 | Lumen | HOLLISTER | – | yes | yes |
| 831-666 | Onvoy | WATSONVL | – | yes | yes |
| 831-667 | AT&T | BIG SUR | – | yes | yes |
| 831-673 | AT&T | HOLLISTER | – | yes | yes |
| 831-674 | AT&T | GREENFIELD | – | yes | yes |
| 831-675 | AT&T | GONZALES | – | yes | yes |
| 831-676 | AT&T | SALINAS | 2002-08-30 | yes | yes |
| 831-677 | MATRIX TELECOM, LLC. S/I/I TNCI - CA | SOLEDAD | – | yes | yes |
| 831-678 | AT&T | SOLEDAD | – | – | yes |
| 831-679 | AT&T | CHUALAR | – | yes | yes |
| 831-682 | Verizon | SALINAS | 2001-03-09 | – | yes |
| 831-684 | AT&T | APTOS | – | yes | yes |
| 831-685 | AT&T | APTOS | – | – | yes |
| 831-687 | AT&T | APTOS | – | yes | yes |
| 831-688 | AT&T | APTOS | – | – | yes |
| 831-689 | AT&T | APTOS | – | yes | yes |
| 831-693 | PINNACLES TEL. CO. | IDRIA | – | – | yes |
| 831-699 | FRACTEL, LLC | FELTON | 2020-12-21 | yes | yes |
| 831-703 | Lumen | BOULDERCRK | – | yes | yes |
| 831-704 | Onvoy | FELTON | – | yes | yes |
| 831-705 | TPx | CHUALAR | 2002-03-13 | yes | yes |
| 831-706 | Lumen | SANTA CRUZ | – | yes | yes |
| 831-707 | Lumen | WATSONVL | – | yes | yes |
| 831-708 | Bandwidth | APTOS | – | yes | yes |
| 831-709 | Lumen | BEN LOMOND | – | yes | yes |
| 831-710 | AT&T | SALINAS | 2002-04-12 | yes | yes |
| 831-713 | Verizon | SANTA CRUZ | – | yes | yes |
| 831-717 | Twilio | MONTEREY | – | yes | yes |
| 831-718 | Verizon | MONTEREY | 2005-08-16 | yes | yes |
| 831-722 | AT&T | WATSONVL | – | – | yes |
| 831-724 | AT&T | WATSONVL | – | – | yes |
| 831-726 | AT&T | WATSONVL | – | yes | yes |
| 831-728 | AT&T | WATSONVL | – | – | yes |
| 831-731 | IP HORIZON LLC | CASTROVL | – | yes | yes |
| 831-732 | Lumen | SAN ARDO | – | yes | yes |
| 831-737 | TPx | SALINAS | 2006-03-28 | yes | yes |
| 831-740 | AT&T | WATSONVL | – | yes | yes |
| 831-741 | Lumen | CASTROVL | – | yes | yes |
| 831-744 | Verizon | GONZALES | – | yes | yes |
| 831-747 | AT&T | MONTEREY | 2005-04-06 | yes | yes |
| 831-750 | T-Mobile | WATSONVL | – | yes | yes |
| 831-751 | AT&T | SALINAS | – | – | yes |
| 831-753 | AT&T | SALINAS | – | – | yes |
| 831-754 | AT&T | SALINAS | – | – | yes |
| 831-755 | AT&T | SALINAS | – | – | yes |
| 831-756 | UTILITY TELECOM GROUP, LLC - CA | SALINAS | 2005-09-12 | yes | yes |
| 831-757 | AT&T | SALINAS | – | – | yes |
| 831-758 | AT&T | SALINAS | – | – | yes |
| 831-759 | AT&T | SALINAS | – | – | yes |
| 831-760 | T-Mobile | MONTEREY | – | yes | yes |
| 831-761 | AT&T | WATSONVL | – | – | yes |
| 831-763 | AT&T | WATSONVL | – | – | yes |
| 831-768 | AT&T | WATSONVL | – | – | yes |
| 831-769 | AT&T | SALINAS | – | yes | yes |
| 831-770 | AT&T | SALINAS | – | yes | yes |
| 831-771 | AT&T | SALINAS | – | – | yes |
| 831-772 | AT&T | SALINAS | – | – | yes |
| 831-774 | T-Mobile | GONZALES | – | yes | yes |
| 831-775 | AT&T | SALINAS | – | yes | yes |
| 831-776 | T-Mobile | SALINAS | 2001-07-12 | yes | yes |
| 831-777 | Onvoy | SANTA CRUZ | 2015-08-17 | yes | yes |
| 831-778 | Lumen | SAN LUCAS | – | yes | yes |
| 831-783 | AT&T | SALINAS | – | yes | yes |
| 831-784 | AT&T | SALINAS | – | yes | yes |
| 831-785 | T-Mobile | SALINAS | – | yes | yes |
| 831-786 | AT&T | WATSONVL | – | yes | yes |
| 831-788 | FRACTEL, LLC | SALINAS | 2022-05-31 | yes | yes |
| 831-789 | MATRIX TELECOM, LLC. S/I/I TNCI - CA | SALINAS | – | yes | yes |
| 831-794 | T-Mobile | SALINAS | 2001-09-13 | yes | yes |
| 831-796 | AT&T | SALINAS | – | yes | yes |
| 831-800 | SKYE TELECOM LLC DBA SKYETEL | SALINAS | – | yes | yes |
| 831-801 | Verizon | HOLLISTER | – | – | yes |
| 831-808 | Charter | SOLEDAD | 2023-12-06 | yes | yes |
| 831-809 | Verizon | SALINAS | – | – | yes |
| 831-818 | Verizon | SANTA CRUZ | – | – | yes |
| 831-821 | Verizon | TRES PINOS | – | yes | yes |
| 831-824 | AT&T | SANTA CRUZ | – | yes | yes |
| 831-830 | Onvoy | KING CITY | 2020-07-24 | yes | yes |
| 831-833 | COMMIO, LLC | HOLLISTER | 2022-02-24 | yes | yes |
| 831-837 | TON80 COMMUNICATIONS, LLC | SALINAS | 2022-01-10 | yes | yes |
| 831-840 | AT&T | WATSONVL | – | yes | yes |
| 831-842 | FRACTEL, LLC | APTOS | 2021-11-21 | yes | yes |
| 831-844 | TON80 COMMUNICATIONS, LLC | BIG SUR | – | yes | yes |
| 831-850 | Onvoy | FELTON | – | yes | yes |
| 831-851 | Onvoy | WATSONVL | – | – | yes |
| 831-854 | MATRIX TELECOM, LLC. S/I/I TNCI - CA | SANTA CRUZ | – | yes | yes |
| 831-855 | Peerless | MONTEREY | – | yes | yes |
| 831-856 | Bandwidth | GREENFIELD | – | yes | yes |
| 831-859 | HD CARRIER LLC | SALINAS | 2024-06-20 | yes | yes |
| 831-867 | COMMIO, LLC | MONTEREY | 2017-03-24 | yes | yes |
| 831-869 | T-Mobile | MONTEREY | 2001-07-12 | yes | yes |
| 831-877 | FRACTEL, LLC | CARMEL | 2019-03-20 | yes | yes |
| 831-880 | 8x8 | MONTEREY | 2026-05-20 | yes | yes |
| 831-881 | WIDE VOICE, LLC - CA | MONTEREY | 2025-10-30 | yes | yes |
| 831-883 | AT&T | MONTEREY | – | yes | yes |
| 831-884 | AT&T | MONTEREY | – | yes | yes |
| 831-886 | NUSO, LLC | MONTEREY | – | yes | yes |
| 831-887 | TERRA NOVA TELECOM INC. | MONTEREY | – | yes | yes |
| 831-888 | Onvoy | SANTA CRUZ | – | yes | yes |
| 831-889 | UTILITY TELECOM GROUP, LLC - CA | SANTA CRUZ | 2018-06-27 | yes | yes |
| 831-899 | AT&T | MONTEREY | – | – | yes |
| 831-900 | Onvoy | SANTA CRUZ | – | yes | yes |
| 831-901 | WAVENATION, LLC | MONTEREY | – | yes | yes |
| 831-902 | T-Mobile | HOLLISTER | – | yes | yes |
| 831-905 | AT&T | SALINAS | – | – | yes |
| 831-915 | AT&T | MONTEREY | – | – | yes |
| 831-917 | AT&T | MONTEREY | – | yes | yes |
| 831-920 | Lumen | MONTEREY | 2005-06-03 | yes | yes |
| 831-921 | Lumen | TRES PINOS | – | yes | yes |
| 831-931 | Charter | KING CITY | 2023-12-06 | yes | yes |
| 831-946 | FRACTEL, LLC | SANTA CRUZ | 2021-07-13 | yes | yes |
| 831-948 | UTILITY TELECOM GROUP, LLC - CA | WATSONVL | 2015-04-03 | yes | yes |
| 831-970 | T-Mobile | SALINAS | – | yes | yes |
| 831-975 | Comcast | SALINAS | – | yes | yes |
| 831-996 | IP HORIZON LLC | TRES PINOS | – | yes | yes |
| 831-998 | Verizon | SALINAS | 2003-07-17 | yes | yes |
| 831-999 | Peerless | SANTA CRUZ | 2016-04-06 | yes | yes |
Frequently asked
How many prefixes does area code 831 have?
406 NXX blocks are assigned of 786 possible. Each block is 10,000 consecutive numbers, so the code currently covers about 4,060 thousand-number ranges across 24 rate centers.
What do the first three digits after 831 tell me?
They identify the block, which tells you the rate center it was allocated to and the carrier that received it. They do not tell you who serves the number today: portability moves numbers between carriers, and pooling splits a block between several of them.
Is a 831 prefix tied to a specific town?
To a rate center, which is billing geography rather than a town. NANPA abbreviates rate center names to ten characters and in large metros uses zone codes, so the name is a NANPA label, not a place name.
What does “pooled” mean in the 831 table?
That the block is in thousands-block pooling: carriers draw 1,000-number lots from it instead of taking all 10,000. 308 of 831's blocks are pooled, which is how regulators slowed down area code exhaustion – and why one prefix can belong to several carriers.
Source and limits
NANPA CO Code Assignment Records, all states, utilized codes, file updated 11/01/2026 – the rows where the record's Use field is “AS” (assigned). Unavailable codes are excluded. The records say who received a block and when, not who serves a particular number today.
More about this code: overview · carriers · spam complaints · local time