All assignees
800 prefixes in 303 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 303-300 | DENVER | 9636 | — | — |
| 303-301 | DENVER | 6118 | — | Yes |
| 303-302 | DENVER | 7229 | — | — |
| 303-303 | DENVER | 321J | 2024-08-26 | Yes |
| 303-304 | FORTLUPTON | 6010 | 2004-11-18 | Yes |
| 303-305 | DENVER | 7229 | — | Yes |
| 303-306 | DENVER | 9636 | — | Yes |
| 303-307 | DENVER | 9636 | — | — |
| 303-308 | DENVER | 9636 | — | — |
| 303-309 | DENVER | 6118 | — | Yes |
| 303-310 | DENVER | 9748 | — | — |
| 303-311 | XXXXXXXXXX | MULT | — | — |
| 303-312 | DENVER | 9636 | — | — |
| 303-313 | DENVER | 9636 | — | — |
| 303-314 | DENVER | 9636 | — | Yes |
| 303-315 | DENVER | 9636 | — | — |
| 303-316 | DENVER | 9636 | — | Yes |
| 303-317 | DENVER | 9636 | — | Yes |
| 303-318 | DENVER | 9636 | — | — |
| 303-319 | DENVER | 765B | 2004-08-12 | Yes |
| 303-320 | DENVER | 9636 | — | — |
| 303-321 | DENVER | 9636 | — | — |
| 303-322 | DENVER | 9636 | — | — |
| 303-323 | DENVER | 7229 | — | Yes |
| 303-324 | DENVER | 6010 | — | — |
| 303-325 | DENVER | 6118 | — | Yes |
| 303-326 | DENVER | 9636 | — | — |
| 303-327 | DENVER | 6118 | — | Yes |
| 303-328 | DENVER | 7229 | — | Yes |
| 303-329 | DENVER | 9636 | — | — |
| 303-330 | DENVER | 026D | 2006-03-09 | Yes |
| 303-331 | DENVER | 9636 | — | — |
| 303-332 | DENVER | 6529 | — | — |
| 303-333 | DENVER | 9636 | — | — |
| 303-334 | DENVER | 7229 | — | — |
| 303-335 | DENVER | 6567 | — | Yes |
| 303-336 | DENVER | 9636 | — | — |
| 303-337 | DENVER | 9636 | — | — |
| 303-338 | DENVER | 9636 | — | — |
| 303-339 | DENVER | 026D | — | Yes |
| 303-340 | DENVER | 9636 | — | — |
| 303-341 | DENVER | 9636 | — | — |
| 303-342 | DENVER | 9636 | — | — |
| 303-343 | DENVER | 9636 | — | — |
| 303-344 | DENVER | 9636 | — | — |
| 303-345 | DENVER | 6118 | — | Yes |
| 303-346 | DENVER | 9636 | — | — |
| 303-347 | DENVER | 9636 | — | — |
| 303-348 | DENVER | 9636 | — | Yes |
| 303-349 | DENVER | 6567 | — | — |
| 303-350 | DENVER | 6010 | — | Yes |
| 303-351 | DECKERS | 026D | 2006-11-08 | Yes |
| 303-352 | DENVER | 9636 | — | — |
| 303-353 | DENVER | 318J | — | Yes |
| 303-354 | DENVER | 7378 | — | Yes |
| 303-355 | DENVER | 9636 | — | — |
| 303-356 | DENVER | 6529 | — | Yes |
| 303-357 | DENVER | 7229 | — | Yes |
| 303-358 | DENVER | 6567 | — | — |
| 303-359 | DENVER | 6529 | — | — |
| 303-360 | DENVER | 9636 | — | — |
| 303-361 | DENVER | 9636 | — | — |
| 303-362 | DENVER | 7378 | — | Yes |
| 303-363 | DENVER | 9636 | — | — |
| 303-364 | DENVER | 9636 | — | — |
| 303-365 | DENVER | 9636 | — | — |
| 303-366 | DENVER | 9636 | — | — |
| 303-367 | DENVER | 9636 | — | — |
| 303-368 | DENVER | 9636 | — | — |
| 303-369 | DENVER | 9636 | — | — |
| 303-370 | DENVER | 9636 | — | — |
| 303-371 | DENVER | 9636 | — | — |
| 303-372 | DENVER | 9636 | — | — |
| 303-373 | DENVER | 9636 | — | — |
| 303-374 | DENVER | 7378 | — | Yes |
| 303-375 | DENVER | 9636 | — | — |
| 303-376 | DENVER | 6118 | — | — |
| 303-377 | DENVER | 9636 | — | — |
| 303-378 | DENVER | 6010 | — | — |
| 303-379 | DENVER | 7378 | — | Yes |
| 303-380 | DENVER | 9636 | — | — |
| 303-381 | DENVER | 6118 | — | — |
| 303-382 | DENVER | 9636 | — | — |
| 303-383 | DENVER | 9636 | — | — |
| 303-384 | DENVER | 9636 | — | — |
| 303-385 | DENVER | 6118 | — | Yes |
| 303-386 | DENVER | 6118 | — | Yes |
| 303-387 | DENVER | 9636 | — | — |
| 303-388 | DENVER | 9636 | — | — |
| 303-389 | DENVER | 9636 | — | Yes |
| 303-390 | DENVER | 7229 | — | — |
| 303-391 | DENVER | 9636 | — | — |
| 303-392 | DENVER | 6567 | 2025-01-16 | Yes |
| 303-393 | DENVER | 9636 | — | — |
| 303-394 | DENVER | 9636 | — | — |
| 303-395 | DENVER | 6118 | — | — |
| 303-396 | DENVER | 3044 | 2005-06-01 | Yes |
| 303-397 | DENVER | 9636 | — | — |
| 303-398 | DENVER | 9636 | — | — |
| 303-399 | DENVER | 9636 | — | — |
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.