T-MOBILE USA, INC.
64 prefixes in 312 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 312-217 | CHICGOZN01 | 6529 | — | Yes |
| 312-221 | CHICGOZN01 | 6529 | 2011-06-17 | Yes |
| 312-285 | CHICGOZN01 | 6529 | — | Yes |
| 312-287 | CHICGOZN07 | 6529 | — | Yes |
| 312-296 | CHICGOZN01 | 6529 | — | Yes |
| 312-340 | CHICGOZN01 | 6529 | — | Yes |
| 312-358 | CHICGOZN01 | 6529 | 2015-07-21 | Yes |
| 312-371 | CHICGOZN01 | 6529 | — | Yes |
| 312-375 | CHICGOZN01 | 6529 | — | — |
| 312-388 | CHICGOZN01 | 6529 | — | Yes |
| 312-399 | CHICGOZN01 | 6529 | — | Yes |
| 312-404 | CHICGOZN01 | 6529 | 2002-10-14 | — |
| 312-434 | CHICGOZN01 | 6529 | 2011-07-08 | Yes |
| 312-437 | CHICGOZN01 | 6529 | — | Yes |
| 312-446 | CHICGOZN01 | 6529 | — | Yes |
| 312-451 | CHICGOZN01 | 6529 | — | Yes |
| 312-459 | CHICGOZN01 | 6529 | 2011-08-02 | Yes |
| 312-468 | CHICGOZN01 | 6529 | 2015-06-26 | Yes |
| 312-476 | CHICGOZN01 | 6529 | — | Yes |
| 312-478 | CHICGOZN01 | 6529 | 2014-03-20 | Yes |
| 312-483 | CHICGOZN01 | 6529 | 2014-08-22 | Yes |
| 312-493 | CHICGOZN01 | 6529 | — | — |
| 312-498 | CHICGOZN01 | 6529 | — | Yes |
| 312-522 | CHICGOZN01 | 6529 | 2014-08-22 | Yes |
| 312-523 | CHICGOZN01 | 6529 | — | Yes |
| 312-532 | CHICGOZN01 | 6529 | — | Yes |
| 312-536 | CHICGOZN01 | 6529 | 2015-06-26 | Yes |
| 312-539 | CHICGOZN01 | 6529 | 2016-01-11 | Yes |
| 312-545 | CHICGOZN01 | 6529 | — | Yes |
| 312-593 | CHICGOZN01 | 6529 | — | — |
| 312-617 | CHICGOZN01 | 6529 | — | Yes |
| 312-619 | CHICGOZN01 | 6529 | 2012-09-11 | Yes |
| 312-647 | CHICGOZN01 | 6529 | 2013-05-24 | Yes |
| 312-656 | CHICGOZN01 | 6529 | — | Yes |
| 312-671 | CHICGOZN01 | 6529 | — | Yes |
| 312-678 | CHICGOZN01 | 6529 | 2013-07-25 | Yes |
| 312-684 | CHICGOZN01 | 6529 | 2016-09-13 | Yes |
| 312-685 | CHICGOZN01 | 6529 | — | Yes |
| 312-687 | CHICGOZN01 | 6529 | 2016-09-13 | Yes |
| 312-709 | CHICGOZN01 | 6529 | 2013-05-24 | Yes |
| 312-719 | CHICGOZN01 | 6529 | — | Yes |
| 312-721 | CHICGOZN01 | 6529 | 2013-10-22 | Yes |
| 312-731 | CHICGOZN01 | 6529 | — | Yes |
| 312-735 | CHICGOZN04 | 6529 | 2001-07-06 | Yes |
| 312-774 | CHICGOZN01 | 6529 | 2013-08-19 | Yes |
| 312-776 | CHICGOZN01 | 6529 | 2019-01-30 | Yes |
| 312-804 | CHICGOZN01 | 6529 | 2002-01-23 | — |
| 312-818 | CHICGOZN01 | 6529 | 2013-08-19 | Yes |
| 312-825 | CHICGOZN01 | 6529 | 2016-03-17 | Yes |
| 312-826 | CHICGOZN01 | 6529 | 2016-06-17 | Yes |
| 312-838 | CHICGOZN01 | 6529 | 2016-01-11 | Yes |
| 312-866 | CHICGOZN01 | 6529 | 2014-08-22 | Yes |
| 312-871 | CHICGOZN01 | 6529 | 2015-08-28 | Yes |
| 312-874 | CHICGOZN01 | 6529 | 2015-05-22 | Yes |
| 312-885 | CHICGOZN01 | 6529 | 2015-09-22 | Yes |
| 312-890 | CHICGOZN01 | 6529 | — | Yes |
| 312-907 | CHICGOZN01 | 6529 | — | Yes |
| 312-918 | CHICGOZN01 | 6529 | 2013-08-19 | Yes |
| 312-927 | CHICGOZN01 | 6529 | 2002-08-21 | — |
| 312-929 | CHICGOZN01 | 6529 | 2006-04-27 | Yes |
| 312-933 | CHICGOZN01 | 6529 | — | Yes |
| 312-934 | CHICGOZN01 | 6529 | 2014-12-08 | Yes |
| 312-975 | CHICGOZN01 | 6529 | 2014-09-15 | Yes |
| 312-978 | CHICGOZN01 | 6529 | 2013-10-22 | Yes |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.