312 Area Code: Location, Cities, Map And Time Zone
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© OpenStreetMap contributorsFor exact NPA boundaries see official 312 area code map
312-300-XXXX --- 312-399-XXXX
312-400-XXXX --- 312-499-XXXX
312-500-XXXX --- 312-599-XXXX
312-600-XXXX --- 312-699-XXXX
312-701-XXXX --- 312-799-XXXX
312-800-XXXX --- 312-899-XXXX
312-900-XXXX --- 312-999-XXXX
Area code 312 is in Illinois, USA , serving the city of Chicago (downtown area); it currently uses 784 prefixes , assigned from 312-200-XXXX through 312-999-XXXX.
In service since January 01, 1947, area code 312 is the parent Numbering Plan Area in overlay complex 312/872.
The rest of the city of Chicago is covered by these overlaying area codes: 773/872.
The current local time is .
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More Illinois area codes:
- 217
- 224
- 309
- 331
- 447
- 464
- 618
- 630
- 708
- 730
- 773
- 779
- 815
- 847
- 861
- 872
Locate any 312-NXX prefix:
312-200-XXXX --- 312-299-XXXX| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-200 | MetroPCS | Chicago Zone 01 | 10/2/2017 |
| 312-201 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-202 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-203 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-204 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-205 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-206 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-207 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-208 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-209 | Cellco Partnership | Northbrook | N/A |
| 312-210 | Peerless Network Of Illinois | Chicago Zone 01 | 7/19/2018 |
| 312-212 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-213 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-214 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-215 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-216 | First Communications | Chicago Zone 01 | 2/13/2012 |
| 312-217 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-218 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-219 | Bandwidth.com Clec | Chicago Zone 01 | 4/10/2012 |
| 312-220 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-221 | T-Mobile USA | Chicago Zone 01 | 6/17/2011 |
| 312-222 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-223 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-224 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-225 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-226 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-227 | Illinois Bell Tel Co | Chicago Zone 01 | 9/15/2010 |
| 312-228 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-229 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-230 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-231 | New Cingular Wireless PCS | Roselle | N/A |
| 312-232 | American Messaging Services | Chicago Zone 01 | 4/23/2001 |
| 312-233 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-234 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-235 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-236 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-237 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-238 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-239 | AT&T | Chicago Zone 01 | N/A |
| 312-240 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-241 | New Cingular Wireless PCS | Chicago Zone 01 | 8/17/2011 |
| 312-242 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-243 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-244 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-245 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-246 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-247 | First Communications | Chicago Zone 01 | 4/6/2004 |
| 312-248 | MetroPCS | Chicago Zone 01 | 7/1/2014 |
| 312-249 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-250 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-251 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-252 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-253 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-254 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-255 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-256 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-257 | Cellco Partnership | Chicago Zone 01 | 8/18/2011 |
| 312-258 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-259 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-260 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-261 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-262 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-263 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-264 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-265 | Access One | Chicago Zone 01 | 11/29/2005 |
| 312-266 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-267 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-268 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-269 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-270 | MetroPCS | Chicago Zone 01 | 1/16/2017 |
| 312-271 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-272 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-273 | Cellco Partnership | Chicago Zone 01 | 9/13/2011 |
| 312-274 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-275 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-276 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-277 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-278 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-279 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-280 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-281 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-282 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-283 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-284 | Xo Illinois | Chicago Zone 01 | N/A |
| 312-285 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-286 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-287 | T-Mobile USA | Chicago Zone 07 | N/A |
| 312-288 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-289 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-290 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-291 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-292 | Bandwidth.com Clec | Chicago Zone 01 | 9/2/2011 |
| 312-293 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-294 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-295 | USA Mobility Wireless | La Grange | N/A |
| 312-296 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-297 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-298 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-299 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-300 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-301 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-302 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-303 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-304 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-305 | Cellco Partnership | Northbrook | N/A |
| 312-306 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-307 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-308 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-309 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-310 | Cellco Partnership | Northbrook | N/A |
| 312-312 | Onvoy | Chicago Zone 01 | 1/19/2018 |
| 312-313 | Onvoy | Chicago Zone 01 | 11/10/2014 |
| 312-314 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-315 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-316 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-317 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-318 | Cellco Partnership | La Grange | N/A |
| 312-319 | MCIMetro Access Transmission Services | Chicago Zone 01 | 4/28/2017 |
| 312-320 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-321 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-322 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-323 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-324 | Level 3 Communications | Chicago Zone 01 | 5/3/2001 |
| 312-325 | Illinois Bell Tel Co | Chicago Zone 01 | 6/24/2003 |
| 312-326 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-327 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-328 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-329 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-330 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-331 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-332 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-333 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-334 | First Communications | Chicago Zone 01 | N/A |
| 312-335 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-336 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-337 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-338 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-339 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-340 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-341 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-342 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-343 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-344 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-345 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-346 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-347 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-348 | Onvoy | Chicago Zone 01 | 11/14/2003 |
| 312-349 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-350 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-351 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-352 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-353 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-354 | New Cingular Wireless PCS | Roselle | N/A |
| 312-355 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-356 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-357 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-358 | T-Mobile USA | Chicago Zone 01 | 7/21/2015 |
| 312-359 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-360 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-361 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-362 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-363 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-364 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-365 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-366 | New Cingular Wireless PCS | Chicago Zone 01 | 2/3/2016 |
| 312-367 | USA Mobility Wireless | La Grange | N/A |
| 312-368 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-369 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-370 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-371 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-372 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-373 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-374 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-375 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-376 | Onvoy | Chicago Zone 01 | 6/11/2004 |
| 312-377 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-378 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-379 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-380 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-381 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-382 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-383 | Teleport Communications America | Chicago Zone 01 | 2/1/2016 |
| 312-384 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-385 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-386 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-387 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-388 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-389 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-390 | American Messaging Services | Chicago Zone 01 | 4/16/2001 |
| 312-391 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-392 | Onvoy | Chicago Zone 01 | 10/23/2017 |
| 312-393 | American Messaging Services | Chicago Zone 01 | 4/23/2001 |
| 312-394 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-395 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-396 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-397 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-398 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-399 | T-Mobile USA | Chicago Zone 01 | N/A |
| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-400 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-401 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-402 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-403 | Cellco Partnership | La Grange | N/A |
| 312-404 | T-Mobile USA | Chicago Zone 01 | 10/14/2002 |
| 312-405 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-406 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-407 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-408 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-409 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-410 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-412 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-413 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-414 | Vonage America | Chicago Zone 01 | 8/12/2016 |
| 312-415 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-416 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-417 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-418 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-419 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-420 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-421 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-422 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-423 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-424 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-425 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-426 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-427 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-428 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-429 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-430 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-431 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-432 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-433 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-434 | T-Mobile USA | Chicago Zone 01 | 7/8/2011 |
| 312-435 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-436 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-437 | MetroPCS | Chicago Zone 01 | N/A |
| 312-438 | Cellco Partnership | Chicago Zone 01 | 6/2/2017 |
| 312-439 | New Cingular Wireless PCS | Chicago Zone 01 | 11/28/2016 |
| 312-440 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-441 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-442 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-443 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-444 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-445 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-446 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-447 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-448 | Cellco Partnership | Chicago Zone 01 | 8/2/2011 |
| 312-449 | Wavenation | Chicago Zone 01 | 4/23/2001 |
| 312-450 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-451 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-452 | Onvoy Spectrum | Chicago Zone 01 | 09/02/2025 |
| 312-453 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-454 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-455 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-456 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-457 | American Messaging Services | Chicago Zone 01 | 4/23/2001 |
| 312-458 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-459 | T-Mobile USA | Chicago Zone 01 | 8/2/2011 |
| 312-460 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-461 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-462 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-463 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-464 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-465 | Paetec Itel | Chicago Zone 01 | 3/26/2009 |
| 312-466 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-467 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-468 | T-Mobile USA | Chicago Zone 01 | 6/26/2015 |
| 312-469 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-470 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-471 | MCIMetro Access Transmission Services | Chicago Zone 01 | 6/26/2015 |
| 312-472 | Illinois Bell Tel Co | Chicago Zone 01 | 10/27/2005 |
| 312-473 | Onvoy | Chicago Zone 01 | 11/15/2006 |
| 312-474 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-475 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-476 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-477 | Level 3 Communications | Chicago Zone 01 | 10/20/2010 |
| 312-478 | T-Mobile USA | Chicago Zone 01 | 3/20/2014 |
| 312-479 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-480 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-481 | MetroPCS | Chicago Zone 01 | 7/7/2017 |
| 312-482 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-483 | T-Mobile USA | Chicago Zone 01 | 8/22/2014 |
| 312-484 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-485 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-486 | MCIMetro Access Transmission Services | Chicago Zone 01 | 4/23/2004 |
| 312-487 | MetroPCS | Chicago Zone 01 | 10/27/2014 |
| 312-488 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-489 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-490 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-491 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-492 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-493 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-494 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-495 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-496 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-497 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-498 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-499 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-500 | Onvoy | Chicago Zone 01 | 5/22/2018 |
| 312-501 | Cellco Partnership | La Grange | N/A |
| 312-502 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-503 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-504 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-505 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-506 | First Communications | Chicago Zone 01 | 5/24/2004 |
| 312-507 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-508 | Peerless Network Of Illinois | Chicago Zone 01 | 3/19/2012 |
| 312-509 | Peerless Network Of Illinois | Chicago Zone 01 | 3/6/2012 |
| 312-510 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-512 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-513 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-514 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-515 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-516 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-517 | MCIMetro Access Transmission Services | Chicago Zone 01 | 2/9/2015 |
| 312-518 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-519 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-520 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-521 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-522 | T-Mobile USA | Chicago Zone 01 | 8/22/2014 |
| 312-523 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-524 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-525 | MCIMetro Access Transmission Services | Chicago Zone 01 | 3/20/2002 |
| 312-526 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-527 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-528 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-529 | AT&T | Chicago Zone 01 | N/A |
| 312-530 | Stratus Networks | Chicago Zone 01 | 7/28/2020 |
| 312-531 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-532 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-533 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-534 | Illinois Bell Tel Co | Chicago Zone 01 | 9/17/2008 |
| 312-535 | Bandwidth.com Clec | Chicago Zone 01 | 7/20/2017 |
| 312-536 | T-Mobile USA | Chicago Zone 01 | 6/26/2015 |
| 312-537 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-538 | MetroPCS | Chicago Zone 01 | 7/21/2017 |
| 312-539 | T-Mobile USA | Chicago Zone 01 | 1/11/2016 |
| 312-540 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-541 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-542 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-543 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-544 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-545 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-546 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-547 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-548 | Level 3 Communications | Chicago Zone 01 | 9/5/2007 |
| 312-549 | Teleport Communications America | Chicago Zone 01 | 9/25/2015 |
| 312-550 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-551 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-552 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-553 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-554 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-556 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-557 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-558 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-559 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-560 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-561 | Cellco Partnership | Chicago Zone 01 | 6/20/2012 |
| 312-562 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-563 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-564 | First Communications | Chicago Zone 01 | 11/13/2006 |
| 312-565 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-566 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-567 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-568 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-569 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-570 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-571 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-572 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-573 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-574 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-575 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-576 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-577 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-578 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-579 | Cellco Partnership | Chicago Zone 01 | 7/25/2017 |
| 312-580 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-581 | New Cingular Wireless PCS | Chicago Zone 01 | 7/31/2017 |
| 312-582 | Illinois Bell Tel Co | Chicago Zone 01 | 5/16/2002 |
| 312-583 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-584 | Voip Innovations | Chicago Zone 01 | 8/14/2018 |
| 312-585 | MCIMetro Access Transmission Services | Chicago Zone 01 | 4/16/2013 |
| 312-586 | Onvoy | Chicago Zone 01 | 5/4/2016 |
| 312-587 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-588 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-589 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-590 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-591 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-592 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-593 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-594 | MCIMetro Access Transmission Services | Chicago Zone 01 | 11/6/2008 |
| 312-595 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-596 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-597 | Cellco Partnership | Chicago Zone 01 | 10/4/2016 |
| 312-598 | Onvoy | Chicago Zone 01 | 1/24/2019 |
| 312-599 | Cellco Partnership | Chicago Zone 01 | 11/21/2016 |
| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-600 | Onvoy | Chicago Zone 01 | 5/1/2012 |
| 312-601 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-602 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-603 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-604 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-605 | Paetec Itel | Chicago Zone 01 | 8/6/2012 |
| 312-606 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-607 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-608 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-609 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-610 | Cellco Partnership | Chicago Zone 01 | 8/6/2012 |
| 312-612 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-613 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-614 | Illinois Bell Tel Co | Chicago Zone 01 | 10/19/2012 |
| 312-615 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-616 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-617 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-618 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-619 | T-Mobile USA | Chicago Zone 01 | 9/11/2012 |
| 312-620 | Bandwidth.com Clec | Chicago Zone 01 | 8/15/2012 |
| 312-621 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-622 | New Cingular Wireless PCS | Chicago Zone 01 | 2/14/2001 |
| 312-623 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-624 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-625 | Level 3 Communications | Chicago Zone 01 | 11/12/2001 |
| 312-626 | Onvoy | Chicago Zone 01 | 2/4/2008 |
| 312-627 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-628 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-629 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-630 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-631 | Centurylink Communications | Chicago Zone 01 | 1/11/2013 |
| 312-632 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-633 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-634 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-635 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-636 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-637 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-638 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-639 | Cellco Partnership | Chicago Zone 01 | 10/19/2017 |
| 312-640 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-641 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-642 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-643 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-644 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-645 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-646 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-647 | T-Mobile USA | Chicago Zone 01 | 5/24/2013 |
| 312-648 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-649 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-650 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-651 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-652 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-653 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-654 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-655 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-656 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-657 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-658 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-659 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-660 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-661 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-662 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-663 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-664 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-665 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-666 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-667 | Peerless Network Of Illinois | Chicago Zone 01 | 8/31/2012 |
| 312-668 | Csc Wireless | Chicago Zone 01 | 5/28/2019 |
| 312-669 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-670 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-671 | MetroPCS | Chicago Zone 01 | N/A |
| 312-672 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-673 | First Communications | Chicago Zone 01 | N/A |
| 312-674 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-675 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-676 | First Communications | Chicago Zone 01 | 6/16/2006 |
| 312-677 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-678 | T-Mobile USA | Chicago Zone 01 | 7/25/2013 |
| 312-680 | Onvoy | Chicago Zone 01 | N/A |
| 312-681 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-682 | Nuso | Chicago Zone 01 | 5/14/2020 |
| 312-683 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-684 | T-Mobile USA | Chicago Zone 01 | 9/13/2016 |
| 312-685 | MetroPCS | Chicago Zone 01 | N/A |
| 312-686 | Peerless Network Of Illinois | Chicago Zone 01 | 12/13/2016 |
| 312-687 | T-Mobile USA | Chicago Zone 01 | 9/13/2016 |
| 312-688 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-689 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-690 | Rclec | Chicago Zone 01 | 5/6/2014 |
| 312-691 | Indiana Paging Network | Chicago Zone 01 | N/A |
| 312-692 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-693 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-694 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-695 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-696 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-697 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-698 | Level 3 Communications | Chicago Zone 01 | 8/23/2001 |
| 312-699 | New Cingular Wireless PCS | Hinsdale | N/A |
| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-701 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-702 | MCIMetro Access Transmission Services | Chicago Zone 01 | 12/31/2012 |
| 312-703 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-704 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-705 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-706 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-707 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-708 | Onvoy Spectrum | Chicago Zone 01 | 02/20/2024 |
| 312-709 | T-Mobile USA | Chicago Zone 01 | 5/24/2013 |
| 312-710 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-712 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-713 | American Messaging Services | Chicago Zone 01 | 4/16/2001 |
| 312-714 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-715 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-716 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-717 | USA Mobility Wireless | La Grange | N/A |
| 312-718 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-719 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-720 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-721 | T-Mobile USA | Chicago Zone 01 | 10/22/2013 |
| 312-722 | Paetec Itel | Chicago Zone 01 | 6/1/2015 |
| 312-723 | New Cingular Wireless PCS | Chicago Zone 01 | 11/28/2016 |
| 312-724 | Bandwidth.com Clec | Chicago Zone 01 | 2/7/2013 |
| 312-725 | Bandwidth.com Clec | Chicago Zone 01 | 10/8/2008 |
| 312-726 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-727 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-728 | Cellco Partnership | Chicago Zone 01 | 10/19/2017 |
| 312-729 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-730 | AT&T | Chicago Zone 01 | N/A |
| 312-731 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-732 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-733 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-734 | Teleport Communications America | Chicago Zone 01 | 9/17/2015 |
| 312-735 | T-Mobile USA | Chicago Zone 04 | 7/6/2001 |
| 312-736 | Teleport Communications America | Chicago Zone 01 | 10/20/2017 |
| 312-737 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-738 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-739 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-740 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-741 | Paetec Itel | Chicago Zone 01 | 10/20/2017 |
| 312-742 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-743 | Illinois Bell Tel Co | Chicago Zone 01 | 11/15/2001 |
| 312-744 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-745 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-746 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-747 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-748 | Onvoy | Chicago Zone 01 | 05/22/2023 |
| 312-749 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-750 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-751 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-752 | Level 3 Communications | Chicago Zone 01 | 4/19/2002 |
| 312-753 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-754 | Level 3 Telecom Of Illinois | Chicago Zone 01 | 2/26/2013 |
| 312-755 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-756 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-757 | Bandwidth.com Clec | Chicago Zone 01 | 3/28/2013 |
| 312-758 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-759 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-760 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-761 | Telengy | Chicago Zone 01 | 5/25/2018 |
| 312-762 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-763 | Comcast IP Phone | Chicago Zone 01 | 5/12/2014 |
| 312-764 | Teleport Communications America | Chicago Zone 01 | 10/20/2016 |
| 312-765 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-766 | Peerless Network Of Illinois | Chicago Zone 01 | 10/17/2016 |
| 312-767 | Bandwidth.com Clec | Chicago Zone 01 | 4/16/2015 |
| 312-768 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-769 | Indiana Paging Network | Chicago Zone 01 | N/A |
| 312-770 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-771 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-772 | New Cingular Wireless PCS | Chicago Zone 01 | 8/18/2008 |
| 312-773 | Onvoy Spectrum | Chicago Zone 01 | 05/19/2023 |
| 312-774 | T-Mobile USA | Chicago Zone 01 | 8/19/2013 |
| 312-775 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-776 | T-Mobile USA | Chicago Zone 01 | 1/30/2019 |
| 312-777 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-778 | Onvoy | Chicago Zone 01 | 5/8/2015 |
| 312-779 | Onvoy | Chicago Zone 01 | 5/13/2019 |
| 312-780 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-781 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-782 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-783 | New Cingular Wireless PCS | Chicago Zone 01 | 8/8/2016 |
| 312-784 | First Communications | Chicago Zone 01 | 7/12/2007 |
| 312-785 | New Cingular Wireless PCS | Chicago Zone 01 | 8/19/2014 |
| 312-786 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-787 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-788 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-789 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-790 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-791 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-792 | MCIMetro Access Transmission Services | Chicago Zone 01 | 11/20/2014 |
| 312-793 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-794 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-795 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-796 | Peerless Network Of Illinois | Chicago Zone 01 | 7/26/2016 |
| 312-797 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-798 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-799 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-800 | Peerless Network Of Illinois | Chicago Zone 01 | 11/20/2012 |
| 312-801 | Nuso | Chicago Zone 01 | 4/29/2013 |
| 312-802 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-803 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-804 | T-Mobile USA | Chicago Zone 01 | 1/23/2002 |
| 312-805 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-806 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-807 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-808 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-809 | MCIMetro Access Transmission Services | Chicago Zone 01 | 10/25/2013 |
| 312-810 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-812 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-813 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-814 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-815 | Airespring | Chicago Zone 01 | 5/7/2018 |
| 312-816 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-817 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-818 | T-Mobile USA | Chicago Zone 01 | 8/19/2013 |
| 312-819 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-820 | Onvoy | Chicago Zone 01 | 1/8/2020 |
| 312-821 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-822 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-823 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-824 | MCIMetro Access Transmission Services | Chicago Zone 01 | 6/20/2016 |
| 312-825 | T-Mobile USA | Chicago Zone 01 | 3/17/2016 |
| 312-826 | T-Mobile USA | Chicago Zone 01 | 6/17/2016 |
| 312-827 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-828 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-829 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-830 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-831 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-832 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-833 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-834 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-835 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-836 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-837 | Comcast IP Phone | Chicago Zone 01 | 9/3/2015 |
| 312-838 | T-Mobile USA | Chicago Zone 01 | 1/11/2016 |
| 312-839 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-840 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-841 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-842 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-843 | Teleport Communications America | Chicago Zone 01 | 3/12/2014 |
| 312-844 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-845 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-846 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-847 | Onvoy | Chicago Zone 01 | 6/28/2019 |
| 312-848 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-849 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-850 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-851 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-852 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-853 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-854 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-855 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-856 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-857 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-858 | Rclec | Chicago Zone 01 | 12/21/2015 |
| 312-859 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-860 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-861 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-862 | Illinois Bell Tel Co | Chicago Zone 01 | 1/25/2006 |
| 312-863 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-864 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-865 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-866 | T-Mobile USA | Chicago Zone 01 | 8/22/2014 |
| 312-867 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-868 | Bandwidth.com Clec | Chicago Zone 01 | 12/4/2015 |
| 312-869 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-870 | First Communications | Chicago Zone 01 | N/A |
| 312-871 | MCIMetro Access Transmission Services | Chicago Zone 01 | 8/28/2015 |
| 312-872 | Level 3 Communications | Chicago Zone 01 | 7/12/2018 |
| 312-873 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-874 | T-Mobile USA | Chicago Zone 01 | 5/22/2015 |
| 312-875 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-876 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-877 | AT&T Enterprises | Chicago Zone 01 | 8/12/2014 |
| 312-878 | Peerless Network Of Illinois | Chicago Zone 01 | 2/4/2008 |
| 312-879 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-880 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-881 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-882 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-883 | Bandwidth.com Clec | Chicago Zone 01 | 11/12/2014 |
| 312-884 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-885 | T-Mobile USA | Chicago Zone 01 | 9/22/2015 |
| 312-886 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-887 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-888 | New Cingular Wireless PCS | Chicago Zone 01 | 1/13/2012 |
| 312-889 | Teleport Communications America | Chicago Zone 01 | 6/25/2015 |
| 312-890 | MetroPCS | Chicago Zone 01 | N/A |
| 312-891 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-892 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-893 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-894 | MCIMetro Access Transmission Services | Chicago Zone 01 | N/A |
| 312-895 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-896 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-897 | MCIMetro Access Transmission Services | Chicago Zone 01 | 3/23/2015 |
| 312-898 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-899 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| NPANXX | Carrier1 | Area Served2 | Date3 |
|---|---|---|---|
| 312-900 | Fractel | Chicago Zone 01 | 1/18/2019 |
| 312-901 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-902 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-903 | American Messaging Services | Chicago Zone 01 | 4/13/2001 |
| 312-904 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-905 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-906 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-907 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-908 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-909 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-910 | Onvoy | Chicago Zone 01 | N/A |
| 312-912 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-913 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-914 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-915 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-917 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-918 | T-Mobile USA | Chicago Zone 01 | 8/19/2013 |
| 312-919 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-920 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-921 | Illinois Bell Tel Co | Chicago Zone 01 | 7/21/2008 |
| 312-922 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-923 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-924 | Paetec Itel | Chicago Zone 01 | N/A |
| 312-925 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-926 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-927 | T-Mobile USA | Chicago Zone 01 | 8/21/2002 |
| 312-928 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-929 | T-Mobile USA | Chicago Zone 01 | 4/27/2006 |
| 312-930 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-931 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-932 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-933 | T-Mobile USA | Chicago Zone 01 | N/A |
| 312-934 | T-Mobile USA | Chicago Zone 01 | 12/8/2014 |
| 312-935 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-936 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-937 | Cellco Partnership | Chicago Zone 01 | 9/25/2014 |
| 312-938 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-939 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-940 | Peerless Network Of Illinois | Chicago Zone 01 | 9/20/2013 |
| 312-941 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-942 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-943 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-944 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-945 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-946 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-947 | Illinois Bell Tel Co | Chicago Zone 01 | 11/18/2010 |
| 312-948 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-949 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-951 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-952 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-953 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-954 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-955 | Rcn Telecom Services Of Illinios | Chicago Zone 01 | N/A |
| 312-956 | New Cingular Wireless PCS | Chicago Zone 01 | 9/29/2014 |
| 312-957 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-960 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-961 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-962 | Level 3 Communications | Chicago Zone 01 | N/A |
| 312-963 | USA Mobility Wireless | Chicago Zone 01 | N/A |
| 312-964 | Onvoy | Chicago Zone 01 | N/A |
| 312-965 | Cellco Partnership | Chicago Zone 01 | N/A |
| 312-966 | MetroPCS | Chicago Zone 01 | 11/18/2014 |
| 312-967 | Bandwidth.com Clec | Chicago Zone 01 | 8/7/2014 |
| 312-968 | Cellco Partnership | La Grange | N/A |
| 312-969 | Cellco Partnership | La Grange | N/A |
| 312-970 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-971 | Bandwidth.com Clec | Chicago Zone 01 | 5/1/2014 |
| 312-972 | New Cingular Wireless PCS | Chicago Zone 01 | N/A |
| 312-973 | MCIMetro Access Transmission Services | Chicago Zone 01 | 2/19/2014 |
| 312-974 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-975 | T-Mobile USA | Chicago Zone 01 | 9/15/2014 |
| 312-977 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-978 | T-Mobile USA | Chicago Zone 01 | 10/22/2013 |
| 312-979 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-980 | Teleport Communications America | Chicago Zone 01 | N/A |
| 312-981 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-982 | Comcast IP Phone | Chicago Zone 01 | 10/7/2014 |
| 312-983 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-984 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-985 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-986 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-987 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-988 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-989 | New Cingular Wireless PCS | Chicago Zone 01 | 6/25/2015 |
| 312-990 | New Cingular Wireless PCS | Hinsdale | N/A |
| 312-991 | New Cingular Wireless PCS | Wheeling | N/A |
| 312-992 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-993 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-994 | Paetec Itel | Chicago Zone 01 | 4/10/2001 |
| 312-995 | Teleport Communications America | Chicago Zone 01 | 8/12/2014 |
| 312-996 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-997 | Illinois Bell Tel Co | Chicago Zone 01 | N/A |
| 312-998 | Centurylink Communications | Chicago Zone 01 | 8/12/2014 |
| 312-999 | MCIMetro Access Transmission Services | Chicago Zone 01 | 8/20/2010 |
- NPA-NXX assigned carrier; with Number Pooling thousand block numbers are often assigned to other carriers as well; moreover, phone numbers can be ported between service providers
- For 'Area served' we list the rate center. In the North American Numbering Plan a rate center is a geographic area used to determine local calling boundaries for billing purposes. Its name is generally a locality, often not the only one served by an NPA-NXX combination.
- Assignment date. N/A - mostly central office codes assigned before 2001.
- NXX prefixes last updated: November 22, 2025
Cities in area code 312
| City1 | County | Time Zone1 |
|---|---|---|
| Chicago (downtown area) | Cook | C |
- Listed above are most places served by USA area code 312. When multiple places in a US state share the same name we list the largest one only. Cities with population over 50,000 are displayed in bold text.
- C stands for Central Time (currently ).
Tag » What Is 312 Area Code
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