Phone numbers in Chicago, Illinois
Chicago has 1826 phone prefixes in area codes 312, 630, 708, 773, 847, 872.
Biggest holders: AT&T (local phone), T-Mobile (including Sprint), AT&T Mobility. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 33%
- Local phone company 33%
- Internet / business phone carrier 27%
- Paging service 4%
- Phone company 3%
Every prefix in Chicago
Search the first six digits of a number in this list. If it's here, the number started in Chicago with the carrier shown. If it isn't, check the Illinois page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 312-200 | MetroPCS (T-Mobile) | Mobile carrier | 2017 |
| 312-201 | AT&T (local phone) | Local phone company | – |
| 312-202 | AT&T (local phone) | Local phone company | – |
| 312-203 | AT&T Mobility | Mobile carrier | – |
| 312-204 | AT&T (local phone) | Local phone company | – |
| 312-205 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-206 | AT&T Mobility | Mobile carrier | – |
| 312-207 | AT&T (local phone) | Local phone company | – |
| 312-208 | AT&T Mobility | Mobile carrier | – |
| 312-210 | Peerless Network Of Illinois | Internet / business phone carrier | – |
| 312-212 | AT&T (local phone) | Local phone company | – |
| 312-213 | AT&T Mobility | Mobile carrier | – |
| 312-214 | AT&T (local phone) | Local phone company | – |
| 312-216 | First Communications | Phone company | 2012 |
| 312-217 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-218 | AT&T Mobility | Mobile carrier | – |
| 312-219 | Bandwidth | Internet / business phone carrier | 2012 |
| 312-220 | AT&T (local phone) | Local phone company | – |
| 312-221 | T-Mobile (including Sprint) | Mobile carrier | 2011 |
| 312-222 | AT&T (local phone) | Local phone company | – |
| 312-223 | AT&T (local phone) | Local phone company | – |
| 312-224 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-225 | AT&T (local phone) | Local phone company | – |
| 312-226 | AT&T (local phone) | Local phone company | – |
| 312-227 | AT&T (local phone) | Local phone company | 2010 |
| 312-228 | AT&T (local phone) | Local phone company | – |
| 312-229 | AT&T (local phone) | Local phone company | – |
| 312-230 | AT&T (local phone) | Local phone company | – |
| 312-232 | American Messaging Services | Paging service | 2001 |
| 312-233 | AT&T (local phone) | Local phone company | – |
| 312-234 | AT&T (local phone) | Local phone company | – |
| 312-235 | AT&T (local phone) | Local phone company | – |
| 312-236 | AT&T (local phone) | Local phone company | – |
| 312-237 | Verizon Wireless | Mobile carrier | – |
| 312-238 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-239 | AT&T (local phone) | Local phone company | – |
| 312-240 | AT&T (local phone) | Local phone company | – |
| 312-241 | AT&T Mobility | Mobile carrier | 2011 |
| 312-242 | Teleport Communications America | Internet / business phone carrier | – |
| 312-243 | AT&T (local phone) | Local phone company | – |
| 312-244 | AT&T (local phone) | Local phone company | – |
| 312-245 | AT&T (local phone) | Local phone company | – |
| 312-247 | First Communications | Phone company | 2004 |
| 312-248 | MetroPCS (T-Mobile) | Mobile carrier | 2014 |
| 312-249 | Spok | Paging service | – |
| 312-250 | Spok | Paging service | – |
| 312-251 | AT&T (local phone) | Local phone company | – |
| 312-252 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-253 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-254 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-255 | AT&T (local phone) | Local phone company | – |
| 312-256 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-257 | Verizon Wireless | Mobile carrier | 2011 |
| 312-258 | AT&T (local phone) | Local phone company | – |
| 312-259 | AT&T Mobility | Mobile carrier | – |
| 312-260 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-261 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-262 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-263 | AT&T (local phone) | Local phone company | – |
| 312-264 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-265 | Access One | Phone company | 2005 |
| 312-266 | AT&T (local phone) | Local phone company | – |
| 312-267 | AT&T (local phone) | Local phone company | – |
| 312-268 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-269 | AT&T (local phone) | Local phone company | – |
| 312-270 | MetroPCS (T-Mobile) | Mobile carrier | 2017 |
| 312-271 | Spok | Paging service | – |
| 312-272 | Spok | Paging service | – |
| 312-273 | Verizon Wireless | Mobile carrier | 2011 |
| 312-274 | AT&T (local phone) | Local phone company | – |
| 312-275 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-276 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-277 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-278 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-279 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-280 | AT&T (local phone) | Local phone company | – |
| 312-281 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-282 | AT&T Mobility | Mobile carrier | – |
| 312-283 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-284 | XO Illinois | Phone company | – |
| 312-285 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-286 | AT&T Mobility | Mobile carrier | – |
| 312-287 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-288 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-289 | Spok | Paging service | – |
| 312-290 | Spok | Paging service | – |
| 312-291 | AT&T (local phone) | Local phone company | – |
| 312-292 | Bandwidth | Internet / business phone carrier | 2011 |
| 312-293 | AT&T (local phone) | Local phone company | – |
| 312-294 | AT&T (local phone) | Local phone company | – |
| 312-296 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-297 | AT&T (local phone) | Local phone company | – |
| 312-298 | Rcn Telecom Services Of Illinios | Phone company | – |
| 312-299 | Spok | Paging service | – |
| 312-300 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-302 | AT&T (local phone) | Local phone company | – |
| 312-306 | AT&T (local phone) | Local phone company | – |
| 312-307 | AT&T Mobility | Mobile carrier | – |
| 312-308 | AT&T (local phone) | Local phone company | – |
| 312-309 | AT&T (local phone) | Local phone company | – |
| 312-312 | Onvoy | Internet / business phone carrier | 2018 |
| 312-313 | Onvoy | Internet / business phone carrier | 2014 |
| 312-315 | AT&T Mobility | Mobile carrier | – |
| 312-316 | AT&T Mobility | Mobile carrier | – |
| 312-319 | MCImetro (Verizon Business) | Internet / business phone carrier | 2017 |
| 312-320 | AT&T Mobility | Mobile carrier | – |
| 312-321 | AT&T (local phone) | Local phone company | – |
| 312-322 | AT&T (local phone) | Local phone company | – |
| 312-323 | American Messaging Services | Paging service | 2001 |
| 312-324 | Level 3 (Lumen) | Internet / business phone carrier | 2001 |
| 312-325 | AT&T (local phone) | Local phone company | 2003 |
| 312-326 | AT&T (local phone) | Local phone company | – |
| 312-327 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-328 | AT&T (local phone) | Local phone company | – |
| 312-329 | AT&T (local phone) | Local phone company | – |
| 312-330 | AT&T Mobility | Mobile carrier | – |
| 312-332 | AT&T (local phone) | Local phone company | – |
| 312-333 | American Messaging Services | Paging service | 2001 |
| 312-334 | First Communications | Phone company | – |
| 312-335 | AT&T (local phone) | Local phone company | – |
| 312-336 | AT&T (local phone) | Local phone company | – |
| 312-337 | AT&T (local phone) | Local phone company | – |
| 312-338 | AT&T (local phone) | Local phone company | – |
| 312-339 | Verizon Wireless | Mobile carrier | – |
| 312-340 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-341 | AT&T (local phone) | Local phone company | – |
| 312-342 | AT&T Mobility | Mobile carrier | – |
| 312-343 | Verizon Wireless | Mobile carrier | – |
| 312-344 | AT&T (local phone) | Local phone company | – |
| 312-345 | AT&T (local phone) | Local phone company | – |
| 312-346 | AT&T (local phone) | Local phone company | – |
| 312-347 | AT&T (local phone) | Local phone company | – |
| 312-348 | Onvoy | Internet / business phone carrier | 2003 |
| 312-349 | Spok | Paging service | – |
| 312-350 | Verizon Wireless | Mobile carrier | – |
| 312-351 | AT&T Mobility | Mobile carrier | – |
| 312-353 | AT&T (local phone) | Local phone company | – |
| 312-355 | AT&T (local phone) | Local phone company | – |
| 312-356 | AT&T (local phone) | Local phone company | – |
| 312-357 | AT&T (local phone) | Local phone company | – |
| 312-358 | T-Mobile (including Sprint) | Mobile carrier | 2015 |
| 312-359 | Spok | Paging service | – |
| 312-360 | AT&T (local phone) | Local phone company | – |
| 312-361 | AT&T (local phone) | Local phone company | – |
| 312-362 | AT&T (local phone) | Local phone company | – |
| 312-363 | Rcn Telecom Services Of Illinios | Phone company | – |
| 312-364 | AT&T (local phone) | Local phone company | – |
| 312-365 | Spok | Paging service | – |
| 312-366 | AT&T Mobility | Mobile carrier | 2016 |
| 312-368 | AT&T (local phone) | Local phone company | – |
| 312-369 | AT&T Mobility | Mobile carrier | – |
| 312-370 | Spok | Paging service | – |
| 312-371 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-372 | AT&T (local phone) | Local phone company | – |
| 312-373 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-374 | AT&T (local phone) | Local phone company | – |
| 312-375 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-376 | Onvoy | Internet / business phone carrier | – |
| 312-377 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-378 | Spok | Paging service | – |
| 312-379 | Windstream (PAETEC) | Internet / business phone carrier | 2001 |
| 312-380 | AT&T (local phone) | Local phone company | – |
| 312-381 | AT&T (local phone) | Local phone company | – |
| 312-382 | AT&T (local phone) | Local phone company | – |
| 312-383 | Teleport Communications America | Internet / business phone carrier | 2016 |
| 312-384 | AT&T (local phone) | Local phone company | – |
| 312-385 | AT&T (local phone) | Local phone company | – |
| 312-386 | AT&T (local phone) | Local phone company | – |
| 312-387 | Spok | Paging service | – |
| 312-388 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-389 | Spok | Paging service | – |
| 312-390 | American Messaging Services | Paging service | 2001 |
| 312-391 | AT&T Mobility | Mobile carrier | – |
| 312-392 | Onvoy | Internet / business phone carrier | 2017 |
| 312-393 | American Messaging Services | Paging service | 2001 |
| 312-394 | AT&T (local phone) | Local phone company | – |
| 312-395 | Teleport Communications America | Internet / business phone carrier | – |
| 312-396 | AT&T (local phone) | Local phone company | – |
| 312-397 | AT&T (local phone) | Local phone company | – |
| 312-398 | Spok | Paging service | – |
| 312-399 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-400 | American Messaging Services | Paging service | 2001 |
| 312-401 | AT&T Mobility | Mobile carrier | – |
| 312-402 | AT&T Mobility | Mobile carrier | – |
| 312-404 | T-Mobile (including Sprint) | Mobile carrier | 2002 |
| 312-405 | Verizon Wireless | Mobile carrier | – |
| 312-407 | AT&T (local phone) | Local phone company | – |
| 312-408 | AT&T (local phone) | Local phone company | – |
| 312-409 | AT&T (local phone) | Local phone company | – |
| 312-410 | AT&T (local phone) | Local phone company | – |
| 312-413 | AT&T (local phone) | Local phone company | – |
| 312-414 | Vonage America | Internet / business phone carrier | 2016 |
| 312-415 | Verizon Wireless | Mobile carrier | – |
| 312-416 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-417 | AT&T (local phone) | Local phone company | – |
| 312-418 | Spok | Paging service | – |
| 312-419 | AT&T (local phone) | Local phone company | – |
| 312-420 | AT&T Mobility | Mobile carrier | – |
| 312-421 | AT&T (local phone) | Local phone company | – |
| 312-422 | AT&T (local phone) | Local phone company | – |
| 312-423 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-424 | AT&T (local phone) | Local phone company | – |
| 312-425 | AT&T (local phone) | Local phone company | – |
| 312-426 | Onvoy | Internet / business phone carrier | 2026 |
| 312-427 | AT&T (local phone) | Local phone company | – |
| 312-428 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-429 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-430 | AT&T (local phone) | Local phone company | – |
| 312-431 | AT&T (local phone) | Local phone company | – |
| 312-432 | AT&T (local phone) | Local phone company | – |
| 312-433 | AT&T (local phone) | Local phone company | – |
| 312-434 | T-Mobile (including Sprint) | Mobile carrier | 2011 |
| 312-435 | AT&T (local phone) | Local phone company | – |
| 312-436 | AT&T (local phone) | Local phone company | – |
| 312-437 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-438 | Verizon Wireless | Mobile carrier | 2017 |
| 312-439 | AT&T Mobility | Mobile carrier | 2016 |
| 312-440 | AT&T (local phone) | Local phone company | – |
| 312-441 | AT&T (local phone) | Local phone company | – |
| 312-442 | AT&T (local phone) | Local phone company | – |
| 312-443 | AT&T (local phone) | Local phone company | – |
| 312-444 | AT&T (local phone) | Local phone company | – |
| 312-445 | AT&T (local phone) | Local phone company | – |
| 312-446 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-447 | AT&T (local phone) | Local phone company | – |
| 312-448 | Verizon Wireless | Mobile carrier | 2011 |
| 312-449 | Wavenation | Phone company | 2025 |
| 312-450 | AT&T Mobility | Mobile carrier | – |
| 312-451 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-452 | Onvoy | Internet / business phone carrier | 2025 |
| 312-453 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-454 | AT&T (local phone) | Local phone company | – |
| 312-455 | AT&T (local phone) | Local phone company | – |
| 312-456 | AT&T (local phone) | Local phone company | – |
| 312-457 | American Messaging Services | Paging service | 2001 |
| 312-458 | AT&T (local phone) | Local phone company | – |
| 312-459 | T-Mobile (including Sprint) | Mobile carrier | 2011 |
| 312-460 | AT&T (local phone) | Local phone company | – |
| 312-461 | AT&T (local phone) | Local phone company | – |
| 312-462 | AT&T (local phone) | Local phone company | – |
| 312-463 | AT&T (local phone) | Local phone company | – |
| 312-464 | AT&T (local phone) | Local phone company | – |
| 312-465 | Windstream (PAETEC) | Internet / business phone carrier | 2009 |
| 312-466 | AT&T (local phone) | Local phone company | – |
| 312-467 | AT&T (local phone) | Local phone company | – |
| 312-468 | T-Mobile (including Sprint) | Mobile carrier | 2015 |
| 312-469 | AT&T (local phone) | Local phone company | – |
| 312-470 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-471 | MCImetro (Verizon Business) | Internet / business phone carrier | 2015 |
| 312-472 | AT&T (local phone) | Local phone company | 2005 |
| 312-473 | Onvoy | Internet / business phone carrier | 2006 |
| 312-474 | AT&T (local phone) | Local phone company | – |
| 312-475 | AT&T (local phone) | Local phone company | – |
| 312-476 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-477 | Level 3 (Lumen) | Internet / business phone carrier | 2010 |
| 312-478 | T-Mobile (including Sprint) | Mobile carrier | 2014 |
| 312-479 | Teleport Communications America | Internet / business phone carrier | – |
| 312-480 | AT&T Mobility | Mobile carrier | – |
| 312-481 | MetroPCS (T-Mobile) | Mobile carrier | 2017 |
| 312-482 | AT&T (local phone) | Local phone company | – |
| 312-483 | T-Mobile (including Sprint) | Mobile carrier | 2014 |
| 312-484 | Spok | Paging service | – |
| 312-485 | Verizon Wireless | Mobile carrier | – |
| 312-486 | MCImetro (Verizon Business) | Internet / business phone carrier | 2004 |
| 312-487 | MetroPCS (T-Mobile) | Mobile carrier | 2014 |
| 312-488 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-489 | Verizon Wireless | Mobile carrier | – |
| 312-490 | Spok | Paging service | – |
| 312-491 | AT&T (local phone) | Local phone company | – |
| 312-492 | AT&T (local phone) | Local phone company | – |
| 312-493 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-494 | AT&T (local phone) | Local phone company | – |
| 312-495 | Spok | Paging service | – |
| 312-496 | AT&T (local phone) | Local phone company | – |
| 312-497 | Verizon Wireless | Mobile carrier | – |
| 312-498 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-499 | AT&T (local phone) | Local phone company | – |
| 312-500 | Onvoy | Internet / business phone carrier | 2018 |
| 312-502 | Verizon Wireless | Mobile carrier | – |
| 312-503 | Teleport Communications America | Internet / business phone carrier | – |
| 312-504 | AT&T Mobility | Mobile carrier | – |
| 312-505 | Verizon Wireless | Mobile carrier | – |
| 312-506 | First Communications | Phone company | 2004 |
| 312-507 | AT&T (local phone) | Local phone company | – |
| 312-508 | Peerless Network Of Illinois | Internet / business phone carrier | 2012 |
| 312-509 | Peerless Network Of Illinois | Internet / business phone carrier | 2012 |
| 312-512 | Spok | Paging service | – |
| 312-513 | AT&T Mobility | Mobile carrier | – |
| 312-514 | American Messaging Services | Paging service | 2001 |
| 312-515 | Verizon Wireless | Mobile carrier | – |
| 312-516 | AT&T (local phone) | Local phone company | – |
| 312-517 | MCImetro (Verizon Business) | Internet / business phone carrier | 2015 |
| 312-519 | Verizon Wireless | Mobile carrier | – |
| 312-520 | Verizon Wireless | Mobile carrier | – |
| 312-521 | Teleport Communications America | Internet / business phone carrier | – |
| 312-522 | T-Mobile (including Sprint) | Mobile carrier | 2014 |
| 312-523 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-525 | MCImetro (Verizon Business) | Internet / business phone carrier | 2002 |
| 312-526 | AT&T (local phone) | Local phone company | – |
| 312-527 | AT&T (local phone) | Local phone company | – |
| 312-528 | AT&T (local phone) | Local phone company | – |
| 312-529 | AT&T (local phone) | Local phone company | – |
| 312-530 | Stratus Networks | Phone company | 2020 |
| 312-532 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-533 | Verizon Wireless | Mobile carrier | – |
| 312-534 | AT&T (local phone) | Local phone company | 2008 |
| 312-535 | Bandwidth | Internet / business phone carrier | 2017 |
| 312-536 | T-Mobile (including Sprint) | Mobile carrier | 2015 |
| 312-537 | AT&T (local phone) | Local phone company | – |
| 312-538 | MetroPCS (T-Mobile) | Mobile carrier | 2017 |
| 312-539 | T-Mobile (including Sprint) | Mobile carrier | 2016 |
| 312-540 | AT&T (local phone) | Local phone company | – |
| 312-541 | AT&T (local phone) | Local phone company | – |
| 312-542 | AT&T (local phone) | Local phone company | – |
| 312-543 | AT&T Mobility | Mobile carrier | – |
| 312-544 | AT&T (local phone) | Local phone company | – |
| 312-545 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-546 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-547 | AT&T Mobility | Mobile carrier | – |
| 312-548 | Level 3 (Lumen) | Internet / business phone carrier | 2007 |
| 312-549 | Teleport Communications America | Internet / business phone carrier | 2015 |
| 312-550 | Verizon Wireless | Mobile carrier | – |
| 312-551 | AT&T (local phone) | Local phone company | – |
| 312-552 | AT&T (local phone) | Local phone company | – |
| 312-553 | AT&T (local phone) | Local phone company | – |
| 312-554 | AT&T (local phone) | Local phone company | – |
| 312-556 | AT&T (local phone) | Local phone company | – |
| 312-557 | AT&T (local phone) | Local phone company | – |
| 312-558 | AT&T (local phone) | Local phone company | – |
| 312-559 | AT&T (local phone) | Local phone company | – |
| 312-560 | AT&T Mobility | Mobile carrier | – |
| 312-561 | Verizon Wireless | Mobile carrier | 2012 |
| 312-562 | Spok | Paging service | – |
| 312-563 | AT&T (local phone) | Local phone company | – |
| 312-564 | First Communications | Phone company | 2006 |
| 312-565 | AT&T (local phone) | Local phone company | – |
| 312-566 | AT&T (local phone) | Local phone company | – |
| 312-567 | AT&T (local phone) | Local phone company | – |
| 312-568 | AT&T (local phone) | Local phone company | – |
| 312-569 | AT&T (local phone) | Local phone company | – |
| 312-570 | AT&T (local phone) | Local phone company | – |
| 312-571 | Spok | Paging service | – |
| 312-572 | AT&T (local phone) | Local phone company | – |
| 312-573 | AT&T (local phone) | Local phone company | – |
| 312-574 | AT&T (local phone) | Local phone company | – |
| 312-575 | AT&T (local phone) | Local phone company | – |
| 312-576 | AT&T Mobility | Mobile carrier | – |
| 312-577 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-578 | AT&T (local phone) | Local phone company | – |
| 312-579 | Verizon Wireless | Mobile carrier | 2017 |
| 312-580 | AT&T (local phone) | Local phone company | – |
| 312-581 | AT&T Mobility | Mobile carrier | 2017 |
| 312-582 | AT&T (local phone) | Local phone company | 2002 |
| 312-583 | AT&T (local phone) | Local phone company | – |
| 312-584 | Voip Innovations | Internet / business phone carrier | 2018 |
| 312-585 | MCImetro (Verizon Business) | Internet / business phone carrier | 2013 |
| 312-586 | Onvoy | Internet / business phone carrier | 2016 |
| 312-587 | AT&T (local phone) | Local phone company | – |
| 312-588 | AT&T (local phone) | Local phone company | – |
| 312-589 | AT&T (local phone) | Local phone company | – |
| 312-590 | Verizon Wireless | Mobile carrier | – |
| 312-591 | AT&T (local phone) | Local phone company | – |
| 312-592 | AT&T (local phone) | Local phone company | – |
| 312-593 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-594 | MCImetro (Verizon Business) | Internet / business phone carrier | 2008 |
| 312-595 | AT&T (local phone) | Local phone company | – |
| 312-596 | Teleport Communications America | Internet / business phone carrier | – |
| 312-597 | Verizon Wireless | Mobile carrier | 2016 |
| 312-598 | Onvoy | Internet / business phone carrier | 2019 |
| 312-599 | Verizon Wireless | Mobile carrier | 2016 |
| 312-600 | Onvoy | Internet / business phone carrier | 2012 |
| 312-601 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-602 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 312-603 | AT&T (local phone) | Local phone company | – |
| 312-604 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-605 | Windstream (PAETEC) | Internet / business phone carrier | 2012 |
| 312-606 | AT&T (local phone) | Local phone company | – |
| 312-607 | AT&T Mobility | Mobile carrier | – |
| 312-608 | AT&T Mobility | Mobile carrier | – |
| 312-609 | AT&T (local phone) | Local phone company | – |
| 312-610 | Verizon Wireless | Mobile carrier | 2012 |
| 312-612 | AT&T (local phone) | Local phone company | – |
| 312-613 | AT&T Mobility | Mobile carrier | – |
| 312-614 | AT&T (local phone) | Local phone company | 2012 |
| 312-616 | AT&T (local phone) | Local phone company | – |
| 312-617 | T-Mobile (including Sprint) | Mobile carrier | – |
| 312-618 | AT&T Mobility | Mobile carrier | – |
| 312-619 | T-Mobile (including Sprint) | Mobile carrier | 2012 |
| 312-620 | Bandwidth | Internet / business phone carrier | 2012 |
| 312-621 | AT&T (local phone) | Local phone company | – |
| 312-622 | AT&T Mobility | Mobile carrier | 2001 |
| 312-623 | AT&T Mobility | Mobile carrier | – |
| 312-624 | Rcn Telecom Services Of Illinios | Phone company | – |
| 312-625 | Level 3 (Lumen) | Internet / business phone carrier | 2001 |
| 312-626 | Onvoy | Internet / business phone carrier | 2008 |
| 312-627 | AT&T (local phone) | Local phone company | – |
| 312-628 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 312-629 | AT&T (local phone) | Local phone company | – |
| 312-630 | AT&T (local phone) | Local phone company | – |
| 312-631 | CenturyLink / Lumen | Local phone company | 2013 |
Showing the first 400 of 1826 prefixes.
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.