All assignees
596 prefixes in 231 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 231-401 | TRAVERSECY | 116F | 2021-12-21 | Yes |
| 231-402 | MUSKEGON | 543C | 2022-01-21 | Yes |
| 231-403 | WILLIAMSBG | 516C | 2011-08-16 | Yes |
| 231-404 | STANWOOD | 6534 | 2004-10-05 | Yes |
| 231-405 | ALDEN | 543C | 2022-02-04 | Yes |
| 231-406 | FALMOUTH | 543C | 2022-02-04 | Yes |
| 231-407 | MECOSTA | 543C | 2022-02-04 | Yes |
| 231-408 | BIG RAPIDS | 6534 | — | Yes |
| 231-409 | TRAVERSECY | 6534 | — | — |
| 231-410 | MANISTEE | 6534 | 2022-08-12 | Yes |
| 231-411 | XXXXXXXXXX | MULT | — | — |
| 231-412 | HARBOR SPG | 991E | 2010-10-11 | Yes |
| 231-413 | KALKASKA | 2964 | 2022-02-14 | Yes |
| 231-414 | NEWAYGO | 6534 | — | Yes |
| 231-415 | DUBLIN | 792K | 2022-12-05 | Yes |
| 231-416 | BIG RAPIDS | 9748 | — | — |
| 231-417 | PETOSKEY | 770E | 2023-01-06 | Yes |
| 231-418 | MARION | 543C | 2023-07-11 | Yes |
| 231-419 | BELLAIRE | 543C | 2023-07-11 | Yes |
| 231-420 | CHEBOYGAN | 6003 | — | — |
| 231-421 | TRAVERSECY | 792K | 2002-02-20 | Yes |
| 231-422 | PELLSTON | 508J | 2015-08-25 | Yes |
| 231-423 | EVART | 991E | — | — |
| 231-424 | CARR | 3535 | 2005-01-27 | Yes |
| 231-425 | LUDINGTON | 2964 | — | Yes |
| 231-426 | RAVENNA | 543C | 2023-07-11 | Yes |
| 231-427 | MACKINAWCY | 516C | 2011-08-17 | Yes |
| 231-428 | MUSKEGON | 543C | 2023-07-14 | Yes |
| 231-429 | CADILLAC | 6003 | 2002-12-05 | — |
| 231-430 | BOYNE CITY | 543C | 2023-07-14 | Yes |
| 231-431 | CLAM RIVER | 543C | 2021-05-19 | Yes |
| 231-432 | NORTHPORT | 6534 | 2002-08-30 | Yes |
| 231-433 | MOORESTOWN | 6003 | 2011-04-29 | Yes |
| 231-434 | MANTON | 6534 | 2014-09-26 | Yes |
| 231-435 | EASTPORT | 543C | 2023-07-14 | Yes |
| 231-436 | MACKINAWCY | 9323 | — | Yes |
| 231-437 | CHARLEVOIX | 2964 | — | Yes |
| 231-438 | HARBOR SPG | 543C | 2023-07-14 | Yes |
| 231-439 | PETOSKEY | 9323 | — | — |
| 231-440 | BALDWIN | 2550 | 2002-08-27 | Yes |
| 231-441 | FIFE LAKE | 2550 | 2002-08-27 | — |
| 231-442 | HARRIETTA | 933G | 2015-12-01 | Yes |
| 231-443 | HONOR | 543C | 2021-01-08 | Yes |
| 231-444 | CADILLAC | 543C | 2015-08-24 | Yes |
| 231-445 | CHEBOYGAN | 6003 | 2004-08-24 | Yes |
| 231-446 | NORTHPORT | 543C | 2023-07-14 | Yes |
| 231-447 | HOLTON | 543C | 2015-12-02 | Yes |
| 231-448 | ST JAMES | 0677 | — | Yes |
| 231-449 | BALDWIN | 792K | 2021-05-13 | Yes |
| 231-450 | HESPERIA | 6534 | 2005-01-19 | Yes |
| 231-451 | WILLIAMSBG | 543C | 2023-07-14 | Yes |
| 231-452 | NEWAYGO | 318J | — | Yes |
| 231-453 | HOLTON | 792K | 2024-03-01 | Yes |
| 231-454 | TRAVERSECY | 5562 | 2021-09-23 | Yes |
| 231-455 | PENTWATER | 543C | 2021-01-08 | Yes |
| 231-456 | GLEN LAKE | 6534 | 2024-09-05 | Yes |
| 231-457 | MUSKEGON | 3535 | — | Yes |
| 231-459 | BOYNE CITY | 829J | 2004-01-09 | Yes |
| 231-460 | BIG RAPIDS | 543C | — | Yes |
| 231-462 | FOUNTAIN | 9323 | — | Yes |
| 231-463 | TRAVERSECY | 6003 | — | Yes |
| 231-464 | FREESOIL | 9323 | — | Yes |
| 231-465 | REED CITY | 6534 | — | Yes |
| 231-466 | EVART | 624H | 2021-07-02 | Yes |
| 231-468 | CADILLAC | 2964 | 2001-02-05 | Yes |
| 231-469 | MUSKEGON | 6534 | 2026-03-19 | Yes |
| 231-475 | MANTON | 991E | — | Yes |
| 231-477 | BRETHREN | 0703 | — | — |
| 231-480 | LUDINGTON | 6120 | 2002-05-23 | Yes |
| 231-484 | EASTJORDAN | 770E | 2013-08-07 | Yes |
| 231-486 | TRAVERSECY | 7157 | — | Yes |
| 231-487 | PETOSKEY | 9323 | — | Yes |
| 231-488 | MANISTEE | 2550 | 2002-08-27 | — |
| 231-489 | PETOSKEY | 116F | 2015-04-21 | Yes |
| 231-492 | TRAVERSECY | 6003 | — | Yes |
| 231-493 | TRAVERSECY | 2964 | 2017-05-17 | Yes |
| 231-494 | BIG RAPIDS | 9748 | — | — |
| 231-495 | BELLAIRE | 6534 | 2016-07-29 | Yes |
| 231-497 | BOYNE CITY | 6534 | — | Yes |
| 231-498 | ELK RAPIDS | 6120 | 2004-10-20 | Yes |
| 231-499 | TRAVERSECY | 6003 | — | — |
| 231-500 | WHITEHALL | 543C | 2019-10-10 | Yes |
| 231-508 | ONEKAMA | 392F | 2008-06-03 | Yes |
| 231-510 | MANISTEE | 6534 | — | — |
| 231-511 | XXXXXXXXXX | MULT | — | — |
| 231-512 | TRAVERSECY | 9748 | — | — |
| 231-514 | CADILLAC | 9748 | — | — |
| 231-515 | EVART | 3535 | 2005-01-19 | Yes |
| 231-516 | PETOSKEY | 9748 | — | — |
| 231-517 | — | — | ||
| 231-518 | KALKASKA | 6120 | 2001-06-18 | Yes |
| 231-519 | NEWAYGO | 6003 | 2002-07-19 | — |
| 231-520 | CHARLEVOIX | 2550 | 2002-08-27 | — |
| 231-522 | LUTHER | 2550 | — | — |
| 231-525 | WOLVERINE | 9323 | — | Yes |
| 231-526 | HARBOR SPG | 9323 | — | — |
| 231-527 | BIG RAPIDS | 9323 | — | Yes |
| 231-529 | BRUTUS | 0702 | — | Yes |
| 231-531 | MUSKEGON | 5562 | 2019-04-09 | Yes |
| 231-533 | BELLAIRE | 0695 | — | Yes |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.