All assignees
800 prefixes in 203 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 203-200 | NEW HAVEN | 199F | 2008-08-14 | Yes |
| 203-201 | NEW HAVEN | 6630 | — | — |
| 203-202 | DARIEN | 4950 | — | Yes |
| 203-203 | GREENWICH | 639C | 2024-09-18 | Yes |
| 203-204 | GUILFORD | 7143 | — | Yes |
| 203-205 | DANBURY | 9147 | — | Yes |
| 203-206 | WATERBURY | 4036 | — | — |
| 203-207 | DANBURY | 9147 | — | Yes |
| 203-208 | BRANFORD | 318J | — | Yes |
| 203-209 | BRIDGEPORT | 6388 | — | — |
| 203-210 | WILTON | 4950 | — | Yes |
| 203-211 | XXXXXXXXXX | MULT | — | — |
| 203-212 | BRIDGEPORT | 4036 | 2008-10-23 | Yes |
| 203-213 | MERIDEN | 4036 | — | — |
| 203-214 | NEW HAVEN | 4036 | — | — |
| 203-215 | NEW HAVEN | 4036 | — | — |
| 203-216 | WESTPORT | 4036 | — | Yes |
| 203-217 | WATERBURY | 4036 | — | — |
| 203-218 | BRIDGEPORT | 4036 | — | — |
| 203-219 | STAMFORD | 4036 | — | — |
| 203-220 | TRUMBULL | 4950 | — | Yes |
| 203-221 | WESTPORT | 9147 | — | — |
| 203-222 | WESTPORT | 9147 | — | — |
| 203-223 | STAMFORD | 6624 | — | Yes |
| 203-224 | BRIDGEPORT | 9147 | — | Yes |
| 203-225 | HUNTINGTON | 9147 | — | — |
| 203-226 | WESTPORT | 9147 | — | — |
| 203-227 | WESTPORT | 9147 | — | — |
| 203-228 | WATERBURY | 6388 | 2002-10-04 | Yes |
| 203-229 | NORWALK | 9147 | — | — |
| 203-230 | NEW HAVEN | 9147 | — | — |
| 203-231 | ANSONIDRBY | 6388 | — | — |
| 203-232 | WATERBURY | 6388 | — | — |
| 203-233 | WATERBURY | 6388 | — | — |
| 203-234 | NEW HAVEN | 9147 | — | — |
| 203-235 | MERIDEN | 9147 | — | — |
| 203-236 | WATERBURY | 9147 | — | — |
| 203-237 | MERIDEN | 9147 | — | — |
| 203-238 | MERIDEN | 9147 | — | — |
| 203-239 | NEW HAVEN | 9147 | — | — |
| 203-240 | DANBURY | 6388 | — | — |
| 203-241 | DANBURY | 6388 | — | — |
| 203-242 | HUNTINGTON | 4950 | — | Yes |
| 203-243 | BRIDGEPORT | 6624 | — | — |
| 203-244 | RIDGEFIELD | 612K | 2003-03-28 | Yes |
| 203-245 | MADISON | 9147 | — | — |
| 203-246 | NORWALK | 6388 | — | Yes |
| 203-247 | NORWALK | 6388 | — | — |
| 203-248 | NEW HAVEN | 9147 | — | — |
| 203-249 | STAMFORD | 6388 | — | — |
| 203-250 | CHESHIRE | 9147 | — | — |
| 203-251 | STAMFORD | 9147 | — | — |
| 203-252 | STAMFORD | 4950 | — | Yes |
| 203-253 | STAMFORD | 6388 | — | — |
| 203-254 | FAIRFIELD | 9147 | — | — |
| 203-255 | FAIRFIELD | 9147 | — | — |
| 203-256 | FAIRFIELD | 9147 | — | — |
| 203-257 | BRIDGEPORT | 6388 | — | — |
| 203-258 | BRIDGEPORT | 6388 | — | — |
| 203-259 | FAIRFIELD | 9147 | — | — |
| 203-260 | BRIDGEPORT | 4036 | — | — |
| 203-261 | TRUMBULL | 9147 | — | — |
| 203-262 | WOODBURY | 9147 | — | Yes |
| 203-263 | WOODBURY | 9147 | — | Yes |
| 203-264 | WOODBURY | 9147 | — | — |
| 203-265 | WALLINGFD | 9147 | — | — |
| 203-266 | WOODBURY | 9147 | — | Yes |
| 203-267 | WOODBURY | 9147 | — | Yes |
| 203-268 | TRUMBULL | 9147 | — | — |
| 203-269 | WALLINGFD | 9147 | — | — |
| 203-270 | NEWTOWN | 9147 | — | — |
| 203-271 | CHESHIRE | 9147 | — | — |
| 203-272 | CHESHIRE | 9147 | — | — |
| 203-273 | STAMFORD | 6388 | 2002-10-22 | Yes |
| 203-274 | STAMFORD | 4036 | — | Yes |
| 203-275 | BRIDGEPORT | 9147 | — | Yes |
| 203-276 | STAMFORD | 4950 | 2003-03-28 | Yes |
| 203-277 | OLDGRNWICH | 7230 | 2003-04-16 | Yes |
| 203-278 | ANSONIDRBY | 6624 | 2001-05-01 | Yes |
| 203-279 | BRIDGEPORT | 6630 | — | — |
| 203-280 | DARIEN | 7230 | 2004-03-24 | Yes |
| 203-281 | NEW HAVEN | 9147 | — | — |
| 203-282 | STAMFORD | 6630 | — | — |
| 203-283 | MILFORD | 4950 | — | Yes |
| 203-284 | WALLINGFD | 9147 | — | — |
| 203-285 | NEW HAVEN | 7143 | — | Yes |
| 203-286 | NORWALK | 829J | — | Yes |
| 203-287 | NEW HAVEN | 9147 | — | — |
| 203-288 | NEW HAVEN | 9147 | — | — |
| 203-289 | DANBURY | 6630 | — | — |
| 203-290 | BRIDGEPORT | 6624 | 2013-11-14 | Yes |
| 203-291 | WESTPORT | 9147 | — | Yes |
| 203-292 | FAIRFIELD | 4950 | — | Yes |
| 203-293 | WESTPORT | 7230 | — | Yes |
| 203-294 | WALLINGFD | 9147 | — | — |
| 203-295 | NORWALK | 7230 | — | Yes |
| 203-296 | BRIDGEPORT | 7230 | — | Yes |
| 203-297 | DANBURY | 7230 | — | Yes |
| 203-298 | NEW HAVEN | 4950 | — | Yes |
| 203-299 | NORWALK | 9147 | — | 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.