All assignees
800 prefixes in 203 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 203-300 | DANBURY | 6624 | 2001-10-25 | Yes |
| 203-301 | MILFORD | 9147 | — | Yes |
| 203-302 | GREENWICH | 7140 | — | Yes |
| 203-303 | WALLINGFD | 7143 | — | Yes |
| 203-304 | NEWTOWN | 7143 | — | Yes |
| 203-305 | ANSONIDRBY | 4036 | — | — |
| 203-306 | MILFORD | 829J | — | Yes |
| 203-307 | FAIRFIELD | 7230 | 2005-01-31 | Yes |
| 203-308 | ANSONIDRBY | 6388 | 2008-10-22 | Yes |
| 203-309 | DARIEN | 5562 | 2007-09-11 | Yes |
| 203-310 | NEW CANAAN | 7230 | 2003-04-16 | Yes |
| 203-311 | XXXXXXXXXX | MULT | — | — |
| 203-312 | DANBURY | 9147 | — | Yes |
| 203-313 | DANBURY | 6388 | — | Yes |
| 203-314 | NEW HAVEN | 6388 | — | — |
| 203-315 | BRANFORD | 9147 | — | — |
| 203-316 | STAMFORD | 9147 | — | — |
| 203-317 | MERIDEN | 9147 | — | Yes |
| 203-318 | MADISON | 9147 | — | Yes |
| 203-319 | FAIRFIELD | 9147 | — | — |
| 203-320 | DARIEN | 7230 | 2003-04-16 | Yes |
| 203-321 | STAMFORD | 9147 | — | Yes |
| 203-322 | STAMFORD | 9147 | — | — |
| 203-323 | STAMFORD | 9147 | — | — |
| 203-324 | STAMFORD | 9147 | — | — |
| 203-325 | STAMFORD | 9147 | — | — |
| 203-326 | STAMFORD | 9147 | — | Yes |
| 203-327 | STAMFORD | 9147 | — | Yes |
| 203-328 | STAMFORD | 9147 | — | — |
| 203-329 | STAMFORD | 9147 | — | — |
| 203-330 | BRIDGEPORT | 9147 | — | — |
| 203-331 | BRIDGEPORT | 9147 | — | Yes |
| 203-332 | BRIDGEPORT | 9147 | — | — |
| 203-333 | BRIDGEPORT | 9147 | — | — |
| 203-334 | BRIDGEPORT | 9147 | — | — |
| 203-335 | BRIDGEPORT | 9147 | — | — |
| 203-336 | BRIDGEPORT | 9147 | — | — |
| 203-337 | BRIDGEPORT | 9147 | — | — |
| 203-338 | BRIDGEPORT | 9147 | — | Yes |
| 203-339 | BRIDGEPORT | 9147 | — | Yes |
| 203-340 | GREENWICH | 4950 | 2003-08-19 | Yes |
| 203-341 | WESTPORT | 9147 | — | — |
| 203-342 | BRIDGEPORT | 6630 | — | — |
| 203-343 | ANSONIDRBY | 4036 | 2012-01-18 | Yes |
| 203-344 | OLDGRNWICH | 4950 | — | Yes |
| 203-345 | BRIDGEPORT | 4950 | — | Yes |
| 203-346 | WATERBURY | 9147 | — | Yes |
| 203-347 | BYRAM | 4800 | 2004-03-11 | Yes |
| 203-348 | STAMFORD | 9147 | — | — |
| 203-349 | WESTPORT | 7143 | — | Yes |
| 203-350 | MADISON | 7143 | — | Yes |
| 203-351 | STAMFORD | 9147 | — | — |
| 203-352 | STAMFORD | 9147 | — | — |
| 203-353 | STAMFORD | 9147 | — | — |
| 203-354 | NORWALK | 4950 | — | Yes |
| 203-355 | STAMFORD | 4950 | — | — |
| 203-356 | STAMFORD | 9147 | — | Yes |
| 203-357 | STAMFORD | 9147 | — | Yes |
| 203-358 | STAMFORD | 9147 | — | Yes |
| 203-359 | STAMFORD | 9147 | — | — |
| 203-360 | BRIDGEPORT | 5562 | 2008-12-10 | Yes |
| 203-361 | NEW HAVEN | 4800 | 2010-12-16 | Yes |
| 203-362 | BRIDGEPORT | 9147 | — | Yes |
| 203-363 | STAMFORD | 9147 | — | Yes |
| 203-364 | NEWTOWN | 9147 | — | Yes |
| 203-365 | BRIDGEPORT | 9147 | — | — |
| 203-366 | BRIDGEPORT | 9147 | — | — |
| 203-367 | BRIDGEPORT | 9147 | — | — |
| 203-368 | BRIDGEPORT | 9147 | — | Yes |
| 203-369 | OLDGRNWICH | 7230 | 2003-10-07 | Yes |
| 203-370 | NEW HAVEN | 9748 | — | — |
| 203-371 | BRIDGEPORT | 9147 | — | — |
| 203-372 | BRIDGEPORT | 9147 | — | — |
| 203-373 | BRIDGEPORT | 9147 | — | — |
| 203-374 | BRIDGEPORT | 9147 | — | — |
| 203-375 | BRIDGEPORT | 9147 | — | — |
| 203-376 | NEW HAVEN | 6388 | — | — |
| 203-377 | BRIDGEPORT | 9147 | — | — |
| 203-378 | BRIDGEPORT | 9147 | — | — |
| 203-379 | MERIDEN | 9147 | — | Yes |
| 203-380 | BRIDGEPORT | 9147 | — | — |
| 203-381 | BRIDGEPORT | 9147 | — | — |
| 203-382 | BRIDGEPORT | 9147 | — | Yes |
| 203-383 | BRIDGEPORT | 9147 | — | Yes |
| 203-384 | BRIDGEPORT | 9147 | — | — |
| 203-385 | BRIDGEPORT | 9147 | — | Yes |
| 203-386 | BRIDGEPORT | 9147 | — | — |
| 203-387 | NEW HAVEN | 9147 | — | — |
| 203-388 | STAMFORD | 7230 | — | Yes |
| 203-389 | NEW HAVEN | 9147 | — | — |
| 203-390 | NEW HAVEN | 7143 | 2015-11-10 | Yes |
| 203-391 | STAMFORD | 7230 | — | Yes |
| 203-392 | NEW HAVEN | 9147 | — | Yes |
| 203-393 | NEW HAVEN | 9147 | — | Yes |
| 203-394 | BRIDGEPORT | 9147 | — | Yes |
| 203-395 | BRIDGEPORT | 5562 | — | Yes |
| 203-396 | BRIDGEPORT | 9147 | — | — |
| 203-397 | NEW HAVEN | 9147 | — | Yes |
| 203-398 | NORWALK | 6630 | — | — |
| 203-399 | STAMFORD | 7230 | — | 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.