Area Code 312
Area code 312 is in Illinois, USA , serving the city of Chicago (downtown area); it currently uses 786 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 .
For exact NPA boundaries see official 312 area code map
Phone number lookup
More Illinois area codes:
Locate any 312-NXX prefix:
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-200 | Chicago Zone 01 | 10/2/2017 |
| 312-201 | Chicago Zone 01 | N/A |
| 312-202 | Chicago Zone 01 | N/A |
| 312-203 | Chicago Zone 01 | N/A |
| 312-204 | Chicago Zone 01 | N/A |
| 312-205 | Chicago Zone 01 | N/A |
| 312-206 | Chicago Zone 01 | N/A |
| 312-207 | Chicago Zone 01 | N/A |
| 312-208 | Chicago Zone 01 | N/A |
| 312-209 | Northbrook | N/A |
| 312-210 | Chicago Zone 01 | 7/19/2018 |
| 312-212 | Chicago Zone 01 | N/A |
| 312-213 | Chicago Zone 01 | N/A |
| 312-214 | Chicago Zone 01 | N/A |
| 312-215 | Wheeling | N/A |
| 312-216 | Chicago Zone 01 | 2/13/2012 |
| 312-217 | Chicago Zone 01 | N/A |
| 312-218 | Chicago Zone 01 | N/A |
| 312-219 | Chicago Zone 01 | 4/10/2012 |
| 312-220 | Chicago Zone 01 | N/A |
| 312-221 | Chicago Zone 01 | 6/17/2011 |
| 312-222 | Chicago Zone 01 | N/A |
| 312-223 | Chicago Zone 01 | N/A |
| 312-224 | Chicago Zone 01 | N/A |
| 312-225 | Chicago Zone 01 | N/A |
| 312-226 | Chicago Zone 01 | N/A |
| 312-227 | Chicago Zone 01 | 9/15/2010 |
| 312-228 | Chicago Zone 01 | N/A |
| 312-229 | Chicago Zone 01 | N/A |
| 312-230 | Chicago Zone 01 | N/A |
| 312-231 | Roselle | N/A |
| 312-232 | Chicago Zone 01 | 4/23/2001 |
| 312-233 | Chicago Zone 01 | N/A |
| 312-234 | Chicago Zone 01 | N/A |
| 312-235 | Chicago Zone 01 | N/A |
| 312-236 | Chicago Zone 01 | N/A |
| 312-237 | Chicago Zone 01 | N/A |
| 312-238 | Chicago Zone 01 | N/A |
| 312-239 | Chicago Zone 01 | N/A |
| 312-240 | Chicago Zone 01 | N/A |
| 312-241 | Chicago Zone 01 | 8/17/2011 |
| 312-242 | Chicago Zone 01 | N/A |
| 312-243 | Chicago Zone 01 | N/A |
| 312-244 | Chicago Zone 01 | N/A |
| 312-245 | Chicago Zone 01 | N/A |
| 312-246 | Wheeling | N/A |
| 312-247 | Chicago Zone 01 | 4/6/2004 |
| 312-248 | Chicago Zone 01 | 7/1/2014 |
| 312-249 | Chicago Zone 01 | N/A |
| 312-250 | Chicago Zone 01 | N/A |
| 312-251 | Chicago Zone 01 | N/A |
| 312-252 | Chicago Zone 01 | N/A |
| 312-253 | Chicago Zone 01 | N/A |
| 312-254 | Chicago Zone 01 | N/A |
| 312-255 | Chicago Zone 01 | N/A |
| 312-256 | Chicago Zone 01 | N/A |
| 312-257 | Chicago Zone 01 | 8/18/2011 |
| 312-258 | Chicago Zone 01 | N/A |
| 312-259 | Chicago Zone 01 | N/A |
| 312-260 | Chicago Zone 01 | N/A |
| 312-261 | Chicago Zone 01 | N/A |
| 312-262 | Chicago Zone 01 | N/A |
| 312-263 | Chicago Zone 01 | N/A |
| 312-264 | Chicago Zone 01 | N/A |
| 312-265 | Chicago Zone 01 | 11/29/2005 |
| 312-266 | Chicago Zone 01 | N/A |
| 312-267 | Chicago Zone 01 | N/A |
| 312-268 | Chicago Zone 01 | N/A |
| 312-269 | Chicago Zone 01 | N/A |
| 312-270 | Chicago Zone 01 | 1/16/2017 |
| 312-271 | Chicago Zone 01 | N/A |
| 312-272 | Chicago Zone 01 | N/A |
| 312-273 | Chicago Zone 01 | 9/13/2011 |
| 312-274 | Chicago Zone 01 | N/A |
| 312-275 | Chicago Zone 01 | N/A |
| 312-276 | Chicago Zone 01 | N/A |
| 312-277 | Chicago Zone 01 | N/A |
| 312-278 | Chicago Zone 01 | N/A |
| 312-279 | Chicago Zone 01 | N/A |
| 312-280 | Chicago Zone 01 | N/A |
| 312-281 | Chicago Zone 01 | N/A |
| 312-282 | Chicago Zone 01 | N/A |
| 312-283 | Chicago Zone 01 | N/A |
| 312-284 | Chicago Zone 01 | N/A |
| 312-285 | Chicago Zone 01 | N/A |
| 312-286 | Chicago Zone 01 | N/A |
| 312-287 | Chicago Zone 07 | N/A |
| 312-288 | Chicago Zone 01 | N/A |
| 312-289 | Chicago Zone 01 | N/A |
| 312-290 | Chicago Zone 01 | N/A |
| 312-291 | Chicago Zone 01 | N/A |
| 312-292 | Chicago Zone 01 | 9/2/2011 |
| 312-293 | Chicago Zone 01 | N/A |
| 312-294 | Chicago Zone 01 | N/A |
| 312-295 | La Grange | N/A |
| 312-296 | Chicago Zone 01 | N/A |
| 312-297 | Chicago Zone 01 | N/A |
| 312-298 | Chicago Zone 01 | N/A |
| 312-299 | Chicago Zone 01 | N/A |
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-300 | Chicago Zone 01 | N/A |
| 312-301 | Hinsdale | N/A |
| 312-302 | Chicago Zone 01 | N/A |
| 312-303 | Wheeling | N/A |
| 312-304 | Hinsdale | N/A |
| 312-305 | Northbrook | N/A |
| 312-306 | Chicago Zone 01 | N/A |
| 312-307 | Chicago Zone 01 | N/A |
| 312-308 | Chicago Zone 01 | N/A |
| 312-309 | Chicago Zone 01 | N/A |
| 312-310 | Northbrook | N/A |
| 312-312 | Chicago Zone 01 | 1/19/2018 |
| 312-313 | Chicago Zone 01 | 11/10/2014 |
| 312-314 | Hinsdale | N/A |
| 312-315 | Chicago Zone 01 | N/A |
| 312-316 | Chicago Zone 01 | N/A |
| 312-317 | Wheeling | N/A |
| 312-318 | La Grange | N/A |
| 312-319 | Chicago Zone 01 | 4/28/2017 |
| 312-320 | Chicago Zone 01 | N/A |
| 312-321 | Chicago Zone 01 | N/A |
| 312-322 | Chicago Zone 01 | N/A |
| 312-323 | Chicago Zone 01 | 4/13/2001 |
| 312-324 | Chicago Zone 01 | 5/3/2001 |
| 312-325 | Chicago Zone 01 | 6/24/2003 |
| 312-326 | Chicago Zone 01 | N/A |
| 312-327 | Chicago Zone 01 | N/A |
| 312-328 | Chicago Zone 01 | N/A |
| 312-329 | Chicago Zone 01 | N/A |
| 312-330 | Chicago Zone 01 | N/A |
| 312-331 | Wheeling | N/A |
| 312-332 | Chicago Zone 01 | N/A |
| 312-333 | Chicago Zone 01 | 4/13/2001 |
| 312-334 | Chicago Zone 01 | N/A |
| 312-335 | Chicago Zone 01 | N/A |
| 312-336 | Chicago Zone 01 | N/A |
| 312-337 | Chicago Zone 01 | N/A |
| 312-338 | Chicago Zone 01 | N/A |
| 312-339 | Chicago Zone 01 | N/A |
| 312-340 | Chicago Zone 01 | N/A |
| 312-341 | Chicago Zone 01 | N/A |
| 312-342 | Chicago Zone 01 | N/A |
| 312-343 | Chicago Zone 01 | N/A |
| 312-344 | Chicago Zone 01 | N/A |
| 312-345 | Chicago Zone 01 | N/A |
| 312-346 | Chicago Zone 01 | N/A |
| 312-347 | Chicago Zone 01 | N/A |
| 312-348 | Chicago Zone 01 | 11/14/2003 |
| 312-349 | Chicago Zone 01 | N/A |
| 312-350 | Chicago Zone 01 | N/A |
| 312-351 | Chicago Zone 01 | N/A |
| 312-352 | Hinsdale | N/A |
| 312-353 | Chicago Zone 01 | N/A |
| 312-354 | Roselle | N/A |
| 312-355 | Chicago Zone 01 | N/A |
| 312-356 | Chicago Zone 01 | N/A |
| 312-357 | Chicago Zone 01 | N/A |
| 312-358 | Chicago Zone 01 | 7/21/2015 |
| 312-359 | Chicago Zone 01 | N/A |
| 312-360 | Chicago Zone 01 | N/A |
| 312-361 | Chicago Zone 01 | N/A |
| 312-362 | Chicago Zone 01 | N/A |
| 312-363 | Chicago Zone 01 | N/A |
| 312-364 | Chicago Zone 01 | N/A |
| 312-365 | Chicago Zone 01 | N/A |
| 312-366 | Chicago Zone 01 | 2/3/2016 |
| 312-367 | La Grange | N/A |
| 312-368 | Chicago Zone 01 | N/A |
| 312-369 | Chicago Zone 01 | N/A |
| 312-370 | Chicago Zone 01 | N/A |
| 312-371 | Chicago Zone 01 | N/A |
| 312-372 | Chicago Zone 01 | N/A |
| 312-373 | Chicago Zone 01 | N/A |
| 312-374 | Chicago Zone 01 | N/A |
| 312-375 | Chicago Zone 01 | N/A |
| 312-376 | Chicago Zone 01 | 6/11/2004 |
| 312-377 | Chicago Zone 01 | N/A |
| 312-378 | Chicago Zone 01 | N/A |
| 312-379 | Chicago Zone 01 | 4/10/2001 |
| 312-380 | Chicago Zone 01 | N/A |
| 312-381 | Chicago Zone 01 | N/A |
| 312-382 | Chicago Zone 01 | N/A |
| 312-383 | Chicago Zone 01 | 2/1/2016 |
| 312-384 | Chicago Zone 01 | N/A |
| 312-385 | Chicago Zone 01 | N/A |
| 312-386 | Chicago Zone 01 | N/A |
| 312-387 | Chicago Zone 01 | N/A |
| 312-388 | Chicago Zone 01 | N/A |
| 312-389 | Chicago Zone 01 | N/A |
| 312-390 | Chicago Zone 01 | 4/16/2001 |
| 312-391 | Chicago Zone 01 | N/A |
| 312-392 | Chicago Zone 01 | 10/23/2017 |
| 312-393 | Chicago Zone 01 | 4/23/2001 |
| 312-394 | Chicago Zone 01 | N/A |
| 312-395 | Chicago Zone 01 | N/A |
| 312-396 | Chicago Zone 01 | N/A |
| 312-397 | Chicago Zone 01 | N/A |
| 312-398 | Chicago Zone 01 | N/A |
| 312-399 | Chicago Zone 01 | N/A |
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-400 | Chicago Zone 01 | 4/13/2001 |
| 312-401 | Chicago Zone 01 | N/A |
| 312-402 | Chicago Zone 01 | N/A |
| 312-403 | La Grange | N/A |
| 312-404 | Chicago Zone 01 | 10/14/2002 |
| 312-405 | Chicago Zone 01 | N/A |
| 312-406 | Wheeling | N/A |
| 312-407 | Chicago Zone 01 | N/A |
| 312-408 | Chicago Zone 01 | N/A |
| 312-409 | Chicago Zone 01 | N/A |
| 312-410 | Chicago Zone 01 | N/A |
| 312-412 | Wheeling | N/A |
| 312-413 | Chicago Zone 01 | N/A |
| 312-414 | Chicago Zone 01 | 8/12/2016 |
| 312-415 | Chicago Zone 01 | N/A |
| 312-416 | Chicago Zone 01 | N/A |
| 312-417 | Chicago Zone 01 | N/A |
| 312-418 | Chicago Zone 01 | N/A |
| 312-419 | Chicago Zone 01 | N/A |
| 312-420 | Chicago Zone 01 | N/A |
| 312-421 | Chicago Zone 01 | N/A |
| 312-422 | Chicago Zone 01 | N/A |
| 312-423 | Chicago Zone 01 | N/A |
| 312-424 | Chicago Zone 01 | N/A |
| 312-425 | Chicago Zone 01 | N/A |
| 312-426 | Chicago Zone 01 | N/A |
| 312-427 | Chicago Zone 01 | N/A |
| 312-428 | Chicago Zone 01 | N/A |
| 312-429 | Chicago Zone 01 | N/A |
| 312-430 | Chicago Zone 01 | N/A |
| 312-431 | Chicago Zone 01 | N/A |
| 312-432 | Chicago Zone 01 | N/A |
| 312-433 | Chicago Zone 01 | N/A |
| 312-434 | Chicago Zone 01 | 7/8/2011 |
| 312-435 | Chicago Zone 01 | N/A |
| 312-436 | Chicago Zone 01 | N/A |
| 312-437 | Chicago Zone 01 | N/A |
| 312-438 | Chicago Zone 01 | 6/2/2017 |
| 312-439 | Chicago Zone 01 | 11/28/2016 |
| 312-440 | Chicago Zone 01 | N/A |
| 312-441 | Chicago Zone 01 | N/A |
| 312-442 | Chicago Zone 01 | N/A |
| 312-443 | Chicago Zone 01 | N/A |
| 312-444 | Chicago Zone 01 | N/A |
| 312-445 | Chicago Zone 01 | N/A |
| 312-446 | Chicago Zone 01 | N/A |
| 312-447 | Chicago Zone 01 | N/A |
| 312-448 | Chicago Zone 01 | 8/2/2011 |
| 312-449 | Chicago Zone 01 | 4/23/2001 |
| 312-450 | Chicago Zone 01 | N/A |
| 312-451 | Chicago Zone 01 | N/A |
| 312-452 | Chicago Zone 01 | 4/13/2001 |
| 312-453 | Chicago Zone 01 | N/A |
| 312-454 | Chicago Zone 01 | N/A |
| 312-455 | Chicago Zone 01 | N/A |
| 312-456 | Chicago Zone 01 | N/A |
| 312-457 | Chicago Zone 01 | 4/23/2001 |
| 312-458 | Chicago Zone 01 | N/A |
| 312-459 | Chicago Zone 01 | 8/2/2011 |
| 312-460 | Chicago Zone 01 | N/A |
| 312-461 | Chicago Zone 01 | N/A |
| 312-462 | Chicago Zone 01 | N/A |
| 312-463 | Chicago Zone 01 | N/A |
| 312-464 | Chicago Zone 01 | N/A |
| 312-465 | Chicago Zone 01 | 3/26/2009 |
| 312-466 | Chicago Zone 01 | N/A |
| 312-467 | Chicago Zone 01 | N/A |
| 312-468 | Chicago Zone 01 | 6/26/2015 |
| 312-469 | Chicago Zone 01 | N/A |
| 312-470 | Chicago Zone 01 | N/A |
| 312-471 | Chicago Zone 01 | 6/26/2015 |
| 312-472 | Chicago Zone 01 | 10/27/2005 |
| 312-473 | Chicago Zone 01 | 11/15/2006 |
| 312-474 | Chicago Zone 01 | N/A |
| 312-475 | Chicago Zone 01 | N/A |
| 312-476 | Chicago Zone 01 | N/A |
| 312-477 | Chicago Zone 01 | 10/20/2010 |
| 312-478 | Chicago Zone 01 | 3/20/2014 |
| 312-479 | Chicago Zone 01 | N/A |
| 312-480 | Chicago Zone 01 | N/A |
| 312-481 | Chicago Zone 01 | 7/7/2017 |
| 312-482 | Chicago Zone 01 | N/A |
| 312-483 | Chicago Zone 01 | 8/22/2014 |
| 312-484 | Chicago Zone 01 | N/A |
| 312-485 | Chicago Zone 01 | N/A |
| 312-486 | Chicago Zone 01 | 4/23/2004 |
| 312-487 | Chicago Zone 01 | 10/27/2014 |
| 312-488 | Chicago Zone 01 | N/A |
| 312-489 | Chicago Zone 01 | N/A |
| 312-490 | Chicago Zone 01 | N/A |
| 312-491 | Chicago Zone 01 | N/A |
| 312-492 | Chicago Zone 01 | N/A |
| 312-493 | Chicago Zone 01 | N/A |
| 312-494 | Chicago Zone 01 | N/A |
| 312-495 | Chicago Zone 01 | N/A |
| 312-496 | Chicago Zone 01 | N/A |
| 312-497 | Chicago Zone 01 | N/A |
| 312-498 | Chicago Zone 01 | N/A |
| 312-499 | Chicago Zone 01 | N/A |
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-500 | Chicago Zone 01 | 5/22/2018 |
| 312-501 | La Grange | N/A |
| 312-502 | Chicago Zone 01 | N/A |
| 312-503 | Chicago Zone 01 | N/A |
| 312-504 | Chicago Zone 01 | N/A |
| 312-505 | Chicago Zone 01 | N/A |
| 312-506 | Chicago Zone 01 | 5/24/2004 |
| 312-507 | Chicago Zone 01 | N/A |
| 312-508 | Chicago Zone 01 | 3/19/2012 |
| 312-509 | Chicago Zone 01 | 3/6/2012 |
| 312-510 | Hinsdale | N/A |
| 312-512 | Chicago Zone 01 | N/A |
| 312-513 | Chicago Zone 01 | N/A |
| 312-514 | Chicago Zone 01 | 4/13/2001 |
| 312-515 | Chicago Zone 01 | N/A |
| 312-516 | Chicago Zone 01 | N/A |
| 312-517 | Chicago Zone 01 | 2/9/2015 |
| 312-518 | Wheeling | N/A |
| 312-519 | Chicago Zone 01 | N/A |
| 312-520 | Chicago Zone 01 | N/A |
| 312-521 | Chicago Zone 01 | N/A |
| 312-522 | Chicago Zone 01 | 8/22/2014 |
| 312-523 | Chicago Zone 01 | N/A |
| 312-524 | Wheeling | N/A |
| 312-525 | Chicago Zone 01 | 3/20/2002 |
| 312-526 | Chicago Zone 01 | N/A |
| 312-527 | Chicago Zone 01 | N/A |
| 312-528 | Chicago Zone 01 | N/A |
| 312-529 | Chicago Zone 01 | N/A |
| 312-530 | Chicago Zone 01 | 7/28/2020 |
| 312-531 | Hinsdale | N/A |
| 312-532 | Chicago Zone 01 | N/A |
| 312-533 | Chicago Zone 01 | N/A |
| 312-534 | Chicago Zone 01 | 9/17/2008 |
| 312-535 | Chicago Zone 01 | 7/20/2017 |
| 312-536 | Chicago Zone 01 | 6/26/2015 |
| 312-537 | Chicago Zone 01 | N/A |
| 312-538 | Chicago Zone 01 | 7/21/2017 |
| 312-539 | Chicago Zone 01 | 1/11/2016 |
| 312-540 | Chicago Zone 01 | N/A |
| 312-541 | Chicago Zone 01 | N/A |
| 312-542 | Chicago Zone 01 | N/A |
| 312-543 | Chicago Zone 01 | N/A |
| 312-544 | Chicago Zone 01 | N/A |
| 312-545 | Chicago Zone 01 | N/A |
| 312-546 | Chicago Zone 01 | N/A |
| 312-547 | Chicago Zone 01 | N/A |
| 312-548 | Chicago Zone 01 | 9/5/2007 |
| 312-549 | Chicago Zone 01 | 9/25/2015 |
| 312-550 | Chicago Zone 01 | N/A |
| 312-551 | Chicago Zone 01 | N/A |
| 312-552 | Chicago Zone 01 | N/A |
| 312-553 | Chicago Zone 01 | N/A |
| 312-554 | Chicago Zone 01 | N/A |
| 312-556 | Chicago Zone 01 | N/A |
| 312-557 | Chicago Zone 01 | N/A |
| 312-558 | Chicago Zone 01 | N/A |
| 312-559 | Chicago Zone 01 | N/A |
| 312-560 | Chicago Zone 01 | N/A |
| 312-561 | Chicago Zone 01 | 6/20/2012 |
| 312-562 | Chicago Zone 01 | N/A |
| 312-563 | Chicago Zone 01 | N/A |
| 312-564 | Chicago Zone 01 | 11/13/2006 |
| 312-565 | Chicago Zone 01 | N/A |
| 312-566 | Chicago Zone 01 | N/A |
| 312-567 | Chicago Zone 01 | N/A |
| 312-568 | Chicago Zone 01 | N/A |
| 312-569 | Chicago Zone 01 | N/A |
| 312-570 | Chicago Zone 01 | N/A |
| 312-571 | Chicago Zone 01 | N/A |
| 312-572 | Chicago Zone 01 | N/A |
| 312-573 | Chicago Zone 01 | N/A |
| 312-574 | Chicago Zone 01 | N/A |
| 312-575 | Chicago Zone 01 | N/A |
| 312-576 | Chicago Zone 01 | N/A |
| 312-577 | Chicago Zone 01 | N/A |
| 312-578 | Chicago Zone 01 | N/A |
| 312-579 | Chicago Zone 01 | 7/25/2017 |
| 312-580 | Chicago Zone 01 | N/A |
| 312-581 | Chicago Zone 01 | 7/31/2017 |
| 312-582 | Chicago Zone 01 | 5/16/2002 |
| 312-583 | Chicago Zone 01 | N/A |
| 312-584 | Chicago Zone 01 | 8/14/2018 |
| 312-585 | Chicago Zone 01 | 4/16/2013 |
| 312-586 | Chicago Zone 01 | 5/4/2016 |
| 312-587 | Chicago Zone 01 | N/A |
| 312-588 | Chicago Zone 01 | N/A |
| 312-589 | Chicago Zone 01 | N/A |
| 312-590 | Chicago Zone 01 | N/A |
| 312-591 | Chicago Zone 01 | N/A |
| 312-592 | Chicago Zone 01 | N/A |
| 312-593 | Chicago Zone 01 | N/A |
| 312-594 | Chicago Zone 01 | 11/6/2008 |
| 312-595 | Chicago Zone 01 | N/A |
| 312-596 | Chicago Zone 01 | N/A |
| 312-597 | Chicago Zone 01 | 10/4/2016 |
| 312-598 | Chicago Zone 01 | 1/24/2019 |
| 312-599 | Chicago Zone 01 | 11/21/2016 |
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-600 | Chicago Zone 01 | 5/1/2012 |
| 312-601 | Chicago Zone 01 | N/A |
| 312-602 | Chicago Zone 01 | N/A |
| 312-603 | Chicago Zone 01 | N/A |
| 312-604 | Chicago Zone 01 | N/A |
| 312-605 | Chicago Zone 01 | 8/6/2012 |
| 312-606 | Chicago Zone 01 | N/A |
| 312-607 | Chicago Zone 01 | N/A |
| 312-608 | Chicago Zone 01 | N/A |
| 312-609 | Chicago Zone 01 | N/A |
| 312-610 | Chicago Zone 01 | 8/6/2012 |
| 312-612 | Chicago Zone 01 | N/A |
| 312-613 | Chicago Zone 01 | N/A |
| 312-614 | Chicago Zone 01 | 10/19/2012 |
| 312-615 | Wheeling | N/A |
| 312-616 | Chicago Zone 01 | N/A |
| 312-617 | Chicago Zone 01 | N/A |
| 312-618 | Chicago Zone 01 | N/A |
| 312-619 | Chicago Zone 01 | 9/11/2012 |
| 312-620 | Chicago Zone 01 | 8/15/2012 |
| 312-621 | Chicago Zone 01 | N/A |
| 312-622 | Chicago Zone 01 | 2/14/2001 |
| 312-623 | Chicago Zone 01 | N/A |
| 312-624 | Chicago Zone 01 | N/A |
| 312-625 | Chicago Zone 01 | 11/12/2001 |
| 312-626 | Chicago Zone 01 | 2/4/2008 |
| 312-627 | Chicago Zone 01 | N/A |
| 312-628 | Chicago Zone 01 | N/A |
| 312-629 | Chicago Zone 01 | N/A |
| 312-630 | Chicago Zone 01 | N/A |
| 312-631 | Chicago Zone 01 | 1/11/2013 |
| 312-632 | Chicago Zone 01 | N/A |
| 312-633 | Chicago Zone 01 | N/A |
| 312-634 | Chicago Zone 01 | N/A |
| 312-635 | Chicago Zone 01 | N/A |
| 312-636 | Chicago Zone 01 | N/A |
| 312-637 | Chicago Zone 01 | N/A |
| 312-638 | Chicago Zone 01 | N/A |
| 312-639 | Chicago Zone 01 | 10/19/2017 |
| 312-640 | Chicago Zone 01 | N/A |
| 312-641 | Chicago Zone 01 | N/A |
| 312-642 | Chicago Zone 01 | N/A |
| 312-643 | Chicago Zone 01 | N/A |
| 312-644 | Chicago Zone 01 | N/A |
| 312-645 | Chicago Zone 01 | N/A |
| 312-646 | Chicago Zone 01 | N/A |
| 312-647 | Chicago Zone 01 | 5/24/2013 |
| 312-648 | Chicago Zone 01 | N/A |
| 312-649 | Chicago Zone 01 | N/A |
| 312-650 | Chicago Zone 01 | N/A |
| 312-651 | Chicago Zone 01 | N/A |
| 312-652 | Chicago Zone 01 | N/A |
| 312-653 | Chicago Zone 01 | N/A |
| 312-654 | Chicago Zone 01 | N/A |
| 312-655 | Chicago Zone 01 | N/A |
| 312-656 | Chicago Zone 01 | N/A |
| 312-657 | Chicago Zone 01 | N/A |
| 312-658 | Chicago Zone 01 | N/A |
| 312-659 | Chicago Zone 01 | N/A |
| 312-660 | Chicago Zone 01 | N/A |
| 312-661 | Chicago Zone 01 | N/A |
| 312-662 | Chicago Zone 01 | N/A |
| 312-663 | Chicago Zone 01 | N/A |
| 312-664 | Chicago Zone 01 | N/A |
| 312-665 | Chicago Zone 01 | N/A |
| 312-666 | Chicago Zone 01 | N/A |
| 312-667 | Chicago Zone 01 | 8/31/2012 |
| 312-668 | Chicago Zone 01 | 5/28/2019 |
| 312-669 | Chicago Zone 01 | N/A |
| 312-670 | Chicago Zone 01 | N/A |
| 312-671 | Chicago Zone 01 | N/A |
| 312-672 | Chicago Zone 01 | N/A |
| 312-673 | Chicago Zone 01 | N/A |
| 312-674 | Chicago Zone 01 | N/A |
| 312-675 | Chicago Zone 01 | N/A |
| 312-676 | Chicago Zone 01 | 6/16/2006 |
| 312-677 | Chicago Zone 01 | N/A |
| 312-678 | Chicago Zone 01 | 7/25/2013 |
| 312-679 | Chicago Zone 01 | 4/23/2001 |
| 312-680 | Chicago Zone 01 | N/A |
| 312-681 | Chicago Zone 01 | N/A |
| 312-682 | Chicago Zone 01 | 5/14/2020 |
| 312-683 | Chicago Zone 01 | N/A |
| 312-684 | Chicago Zone 01 | 9/13/2016 |
| 312-685 | Chicago Zone 01 | N/A |
| 312-686 | Chicago Zone 01 | 12/13/2016 |
| 312-687 | Chicago Zone 01 | 9/13/2016 |
| 312-688 | Chicago Zone 01 | N/A |
| 312-689 | Chicago Zone 01 | 4/13/2001 |
| 312-690 | Chicago Zone 01 | 5/6/2014 |
| 312-691 | Chicago Zone 01 | N/A |
| 312-692 | Chicago Zone 01 | N/A |
| 312-693 | Chicago Zone 01 | N/A |
| 312-694 | Chicago Zone 01 | N/A |
| 312-695 | Chicago Zone 01 | N/A |
| 312-696 | Chicago Zone 01 | N/A |
| 312-697 | Chicago Zone 01 | N/A |
| 312-698 | Chicago Zone 01 | 8/23/2001 |
| 312-699 | Hinsdale | N/A |
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-701 | Chicago Zone 01 | N/A |
| 312-702 | Chicago Zone 01 | 12/31/2012 |
| 312-703 | Chicago Zone 01 | N/A |
| 312-704 | Chicago Zone 01 | N/A |
| 312-705 | Chicago Zone 01 | N/A |
| 312-706 | Chicago Zone 01 | N/A |
| 312-707 | Chicago Zone 01 | N/A |
| 312-708 | Chicago Zone 01 | 02/20/2024 |
| 312-709 | Chicago Zone 01 | 5/24/2013 |
| 312-710 | Chicago Zone 01 | N/A |
| 312-712 | Chicago Zone 01 | N/A |
| 312-713 | Chicago Zone 01 | 4/16/2001 |
| 312-714 | Chicago Zone 01 | N/A |
| 312-715 | Chicago Zone 01 | N/A |
| 312-716 | Chicago Zone 01 | N/A |
| 312-717 | La Grange | N/A |
| 312-718 | Chicago Zone 01 | N/A |
| 312-719 | Chicago Zone 01 | N/A |
| 312-720 | Chicago Zone 01 | N/A |
| 312-721 | Chicago Zone 01 | 10/22/2013 |
| 312-722 | Chicago Zone 01 | 6/1/2015 |
| 312-723 | Chicago Zone 01 | 11/28/2016 |
| 312-724 | Chicago Zone 01 | 2/7/2013 |
| 312-725 | Chicago Zone 01 | 10/8/2008 |
| 312-726 | Chicago Zone 01 | N/A |
| 312-727 | Chicago Zone 01 | N/A |
| 312-728 | Chicago Zone 01 | 10/19/2017 |
| 312-729 | Chicago Zone 01 | N/A |
| 312-730 | Chicago Zone 01 | N/A |
| 312-731 | Chicago Zone 01 | N/A |
| 312-732 | Chicago Zone 01 | N/A |
| 312-733 | Chicago Zone 01 | N/A |
| 312-734 | Chicago Zone 01 | 9/17/2015 |
| 312-735 | Chicago Zone 04 | 7/6/2001 |
| 312-736 | Chicago Zone 01 | 10/20/2017 |
| 312-737 | Chicago Zone 01 | N/A |
| 312-738 | Chicago Zone 01 | N/A |
| 312-739 | Chicago Zone 01 | N/A |
| 312-740 | Chicago Zone 01 | 4/13/2001 |
| 312-741 | Chicago Zone 01 | 10/20/2017 |
| 312-742 | Chicago Zone 01 | N/A |
| 312-743 | Chicago Zone 01 | 11/15/2001 |
| 312-744 | Chicago Zone 01 | N/A |
| 312-745 | Chicago Zone 01 | N/A |
| 312-746 | Chicago Zone 01 | N/A |
| 312-747 | Chicago Zone 01 | N/A |
| 312-748 | Chicago Zone 01 | 05/22/2023 |
| 312-749 | Hinsdale | N/A |
| 312-750 | Chicago Zone 01 | N/A |
| 312-751 | Chicago Zone 01 | N/A |
| 312-752 | Chicago Zone 01 | 4/19/2002 |
| 312-753 | Chicago Zone 01 | N/A |
| 312-754 | Chicago Zone 01 | 2/26/2013 |
| 312-755 | Chicago Zone 01 | N/A |
| 312-756 | Chicago Zone 01 | N/A |
| 312-757 | Chicago Zone 01 | 3/28/2013 |
| 312-758 | Chicago Zone 01 | N/A |
| 312-759 | Chicago Zone 01 | N/A |
| 312-760 | Chicago Zone 01 | 4/13/2001 |
| 312-761 | Chicago Zone 01 | 5/25/2018 |
| 312-762 | Chicago Zone 01 | N/A |
| 312-763 | Chicago Zone 01 | 5/12/2014 |
| 312-764 | Chicago Zone 01 | 10/20/2016 |
| 312-765 | Chicago Zone 01 | N/A |
| 312-766 | Chicago Zone 01 | 10/17/2016 |
| 312-767 | Chicago Zone 01 | 4/16/2015 |
| 312-768 | Chicago Zone 01 | N/A |
| 312-769 | Chicago Zone 01 | N/A |
| 312-770 | Chicago Zone 01 | N/A |
| 312-771 | Chicago Zone 01 | N/A |
| 312-772 | Chicago Zone 01 | 8/18/2008 |
| 312-773 | Chicago Zone 01 | 05/19/2023 |
| 312-774 | Chicago Zone 01 | 8/19/2013 |
| 312-775 | Chicago Zone 01 | N/A |
| 312-776 | Chicago Zone 01 | 1/30/2019 |
| 312-777 | Chicago Zone 01 | N/A |
| 312-778 | Chicago Zone 01 | 5/8/2015 |
| 312-779 | Chicago Zone 01 | 5/13/2019 |
| 312-780 | Chicago Zone 01 | N/A |
| 312-781 | Chicago Zone 01 | N/A |
| 312-782 | Chicago Zone 01 | N/A |
| 312-783 | Chicago Zone 01 | 8/8/2016 |
| 312-784 | Chicago Zone 01 | 7/12/2007 |
| 312-785 | Chicago Zone 01 | 8/19/2014 |
| 312-786 | Chicago Zone 01 | N/A |
| 312-787 | Chicago Zone 01 | N/A |
| 312-788 | Chicago Zone 01 | N/A |
| 312-789 | Chicago Zone 01 | N/A |
| 312-790 | Chicago Zone 01 | N/A |
| 312-791 | Chicago Zone 01 | N/A |
| 312-792 | Chicago Zone 01 | 11/20/2014 |
| 312-793 | Chicago Zone 01 | N/A |
| 312-794 | Chicago Zone 01 | N/A |
| 312-795 | Chicago Zone 01 | N/A |
| 312-796 | Chicago Zone 01 | 7/26/2016 |
| 312-797 | Chicago Zone 01 | N/A |
| 312-798 | Chicago Zone 01 | N/A |
| 312-799 | Chicago Zone 01 | N/A |
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-800 | Chicago Zone 01 | 11/20/2012 |
| 312-801 | Chicago Zone 01 | 4/29/2013 |
| 312-802 | Chicago Zone 01 | N/A |
| 312-803 | Chicago Zone 01 | N/A |
| 312-804 | Chicago Zone 01 | 1/23/2002 |
| 312-805 | Chicago Zone 01 | N/A |
| 312-806 | Chicago Zone 01 | N/A |
| 312-807 | Chicago Zone 01 | N/A |
| 312-808 | Chicago Zone 01 | N/A |
| 312-809 | Chicago Zone 01 | 10/25/2013 |
| 312-810 | Chicago Zone 01 | N/A |
| 312-812 | Chicago Zone 01 | N/A |
| 312-813 | Chicago Zone 01 | N/A |
| 312-814 | Chicago Zone 01 | N/A |
| 312-815 | Chicago Zone 01 | 5/7/2018 |
| 312-816 | Hinsdale | N/A |
| 312-817 | Chicago Zone 01 | N/A |
| 312-818 | Chicago Zone 01 | 8/19/2013 |
| 312-819 | Chicago Zone 01 | N/A |
| 312-820 | Chicago Zone 01 | 1/8/2020 |
| 312-821 | Chicago Zone 01 | N/A |
| 312-822 | Chicago Zone 01 | N/A |
| 312-823 | Chicago Zone 01 | N/A |
| 312-824 | Chicago Zone 01 | 6/20/2016 |
| 312-825 | Chicago Zone 01 | 3/17/2016 |
| 312-826 | Chicago Zone 01 | 6/17/2016 |
| 312-827 | Chicago Zone 01 | N/A |
| 312-828 | Chicago Zone 01 | N/A |
| 312-829 | Chicago Zone 01 | N/A |
| 312-830 | Chicago Zone 01 | N/A |
| 312-831 | Chicago Zone 01 | N/A |
| 312-832 | Chicago Zone 01 | N/A |
| 312-833 | Chicago Zone 01 | N/A |
| 312-834 | Chicago Zone 01 | N/A |
| 312-835 | Chicago Zone 01 | N/A |
| 312-836 | Chicago Zone 01 | N/A |
| 312-837 | Chicago Zone 01 | 9/3/2015 |
| 312-838 | Chicago Zone 01 | 1/11/2016 |
| 312-839 | Chicago Zone 01 | 4/13/2001 |
| 312-840 | Chicago Zone 01 | N/A |
| 312-841 | Chicago Zone 01 | N/A |
| 312-842 | Chicago Zone 01 | N/A |
| 312-843 | Chicago Zone 01 | 3/12/2014 |
| 312-844 | Hinsdale | N/A |
| 312-845 | Chicago Zone 01 | N/A |
| 312-846 | Chicago Zone 01 | N/A |
| 312-847 | Chicago Zone 01 | 6/28/2019 |
| 312-848 | Chicago Zone 01 | N/A |
| 312-849 | Chicago Zone 01 | N/A |
| 312-850 | Chicago Zone 01 | N/A |
| 312-851 | Chicago Zone 01 | N/A |
| 312-852 | Chicago Zone 01 | N/A |
| 312-853 | Chicago Zone 01 | N/A |
| 312-854 | Chicago Zone 01 | N/A |
| 312-855 | Chicago Zone 01 | N/A |
| 312-856 | Chicago Zone 01 | N/A |
| 312-857 | Chicago Zone 01 | N/A |
| 312-858 | Chicago Zone 01 | 12/21/2015 |
| 312-859 | Chicago Zone 01 | N/A |
| 312-860 | Chicago Zone 01 | N/A |
| 312-861 | Chicago Zone 01 | N/A |
| 312-862 | Chicago Zone 01 | 1/25/2006 |
| 312-863 | Chicago Zone 01 | 4/10/2001 |
| 312-864 | Chicago Zone 01 | N/A |
| 312-865 | Wheeling | N/A |
| 312-866 | Chicago Zone 01 | 8/22/2014 |
| 312-867 | Chicago Zone 01 | N/A |
| 312-868 | Chicago Zone 01 | 12/4/2015 |
| 312-869 | Chicago Zone 01 | N/A |
| 312-870 | Chicago Zone 01 | N/A |
| 312-871 | Chicago Zone 01 | 8/28/2015 |
| 312-872 | Chicago Zone 01 | 7/12/2018 |
| 312-873 | Chicago Zone 01 | N/A |
| 312-874 | Chicago Zone 01 | 5/22/2015 |
| 312-875 | Chicago Zone 01 | N/A |
| 312-876 | Chicago Zone 01 | N/A |
| 312-877 | Chicago Zone 01 | 8/12/2014 |
| 312-878 | Chicago Zone 01 | 2/4/2008 |
| 312-879 | Chicago Zone 01 | N/A |
| 312-880 | Chicago Zone 01 | N/A |
| 312-881 | Chicago Zone 01 | 4/10/2001 |
| 312-882 | Chicago Zone 01 | N/A |
| 312-883 | Chicago Zone 01 | 11/12/2014 |
| 312-884 | Chicago Zone 01 | 4/10/2001 |
| 312-885 | Chicago Zone 01 | 9/22/2015 |
| 312-886 | Chicago Zone 01 | N/A |
| 312-887 | Chicago Zone 01 | N/A |
| 312-888 | Chicago Zone 01 | 1/13/2012 |
| 312-889 | Chicago Zone 01 | 6/25/2015 |
| 312-890 | Chicago Zone 01 | N/A |
| 312-891 | Chicago Zone 01 | N/A |
| 312-892 | Chicago Zone 01 | N/A |
| 312-893 | Chicago Zone 01 | N/A |
| 312-894 | Chicago Zone 01 | N/A |
| 312-895 | Chicago Zone 01 | N/A |
| 312-896 | Chicago Zone 01 | N/A |
| 312-897 | Chicago Zone 01 | 3/23/2015 |
| 312-898 | Chicago Zone 01 | N/A |
| 312-899 | Chicago Zone 01 | N/A |
| NPANXX | Area Served1 | Date1 |
|---|---|---|
| 312-900 | Chicago Zone 01 | 1/18/2019 |
| 312-901 | Chicago Zone 01 | N/A |
| 312-902 | Chicago Zone 01 | N/A |
| 312-903 | Chicago Zone 01 | 4/13/2001 |
| 312-904 | Chicago Zone 01 | N/A |
| 312-905 | Chicago Zone 01 | N/A |
| 312-906 | Chicago Zone 01 | N/A |
| 312-907 | Chicago Zone 01 | N/A |
| 312-908 | Chicago Zone 01 | N/A |
| 312-909 | Chicago Zone 01 | N/A |
| 312-910 | Chicago Zone 01 | N/A |
| 312-912 | Chicago Zone 01 | N/A |
| 312-913 | Chicago Zone 01 | N/A |
| 312-914 | Chicago Zone 01 | N/A |
| 312-915 | Chicago Zone 01 | N/A |
| 312-916 | Chicago Zone 01 | 4/23/2001 |
| 312-917 | Chicago Zone 01 | N/A |
| 312-918 | Chicago Zone 01 | 8/19/2013 |
| 312-919 | Chicago Zone 01 | N/A |
| 312-920 | Chicago Zone 01 | N/A |
| 312-921 | Chicago Zone 01 | 7/21/2008 |
| 312-922 | Chicago Zone 01 | N/A |
| 312-923 | Chicago Zone 01 | N/A |
| 312-924 | Chicago Zone 01 | N/A |
| 312-925 | Chicago Zone 01 | N/A |
| 312-926 | Chicago Zone 01 | N/A |
| 312-927 | Chicago Zone 01 | 8/21/2002 |
| 312-928 | Chicago Zone 01 | N/A |
| 312-929 | Chicago Zone 01 | 4/27/2006 |
| 312-930 | Chicago Zone 01 | N/A |
| 312-931 | Chicago Zone 01 | N/A |
| 312-932 | Chicago Zone 01 | N/A |
| 312-933 | Chicago Zone 01 | N/A |
| 312-934 | Chicago Zone 01 | 12/8/2014 |
| 312-935 | Chicago Zone 01 | N/A |
| 312-936 | Chicago Zone 01 | N/A |
| 312-937 | Chicago Zone 01 | 9/25/2014 |
| 312-938 | Chicago Zone 01 | N/A |
| 312-939 | Chicago Zone 01 | N/A |
| 312-940 | Chicago Zone 01 | 9/20/2013 |
| 312-941 | Chicago Zone 01 | N/A |
| 312-942 | Chicago Zone 01 | N/A |
| 312-943 | Chicago Zone 01 | N/A |
| 312-944 | Chicago Zone 01 | N/A |
| 312-945 | Chicago Zone 01 | N/A |
| 312-946 | Chicago Zone 01 | N/A |
| 312-947 | Chicago Zone 01 | 11/18/2010 |
| 312-948 | Chicago Zone 01 | 4/10/2001 |
| 312-949 | Chicago Zone 01 | N/A |
| 312-951 | Chicago Zone 01 | N/A |
| 312-952 | Chicago Zone 01 | N/A |
| 312-953 | Chicago Zone 01 | N/A |
| 312-954 | Chicago Zone 01 | N/A |
| 312-955 | Chicago Zone 01 | N/A |
| 312-956 | Chicago Zone 01 | 9/29/2014 |
| 312-957 | Chicago Zone 01 | N/A |
| 312-960 | Chicago Zone 01 | N/A |
| 312-961 | Chicago Zone 01 | N/A |
| 312-962 | Chicago Zone 01 | N/A |
| 312-963 | Chicago Zone 01 | N/A |
| 312-964 | Chicago Zone 01 | N/A |
| 312-965 | Chicago Zone 01 | N/A |
| 312-966 | Chicago Zone 01 | 11/18/2014 |
| 312-967 | Chicago Zone 01 | 8/7/2014 |
| 312-968 | La Grange | N/A |
| 312-969 | La Grange | N/A |
| 312-970 | Chicago Zone 01 | N/A |
| 312-971 | Chicago Zone 01 | 5/1/2014 |
| 312-972 | Chicago Zone 01 | N/A |
| 312-973 | Chicago Zone 01 | 2/19/2014 |
| 312-974 | Chicago Zone 01 | N/A |
| 312-975 | Chicago Zone 01 | 9/15/2014 |
| 312-977 | Chicago Zone 01 | N/A |
| 312-978 | Chicago Zone 01 | 10/22/2013 |
| 312-979 | Chicago Zone 01 | N/A |
| 312-980 | Chicago Zone 01 | N/A |
| 312-981 | Chicago Zone 01 | 4/10/2001 |
| 312-982 | Chicago Zone 01 | 10/7/2014 |
| 312-983 | Chicago Zone 01 | N/A |
| 312-984 | Chicago Zone 01 | N/A |
| 312-985 | Chicago Zone 01 | 4/10/2001 |
| 312-986 | Chicago Zone 01 | N/A |
| 312-987 | Chicago Zone 01 | N/A |
| 312-988 | Chicago Zone 01 | N/A |
| 312-989 | Chicago Zone 01 | 6/25/2015 |
| 312-990 | Hinsdale | N/A |
| 312-991 | Wheeling | N/A |
| 312-992 | Chicago Zone 01 | N/A |
| 312-993 | Chicago Zone 01 | N/A |
| 312-994 | Chicago Zone 01 | 4/10/2001 |
| 312-995 | Chicago Zone 01 | 8/12/2014 |
| 312-996 | Chicago Zone 01 | N/A |
| 312-997 | Chicago Zone 01 | N/A |
| 312-998 | Chicago Zone 01 | 8/12/2014 |
| 312-999 | Chicago Zone 01 | 8/20/2010 |
- 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: June 3, 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 ).