MCIMETRO ACCESS TRANSMISSION SERVICES LLC
33 prefixes in 312 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 312-205 | CHICGOZN01 | 7229 | — | — |
| 312-252 | CHICGOZN01 | 7229 | — | Yes |
| 312-253 | CHICGOZN01 | 7229 | — | Yes |
| 312-254 | CHICGOZN01 | 7229 | — | Yes |
| 312-256 | CHICGOZN01 | 7229 | — | Yes |
| 312-260 | CHICGOZN01 | 7229 | — | Yes |
| 312-262 | CHICGOZN01 | 7229 | — | Yes |
| 312-275 | CHICGOZN01 | 7229 | — | — |
| 312-276 | CHICGOZN01 | 7229 | — | — |
| 312-277 | CHICGOZN01 | 7229 | — | — |
| 312-279 | CHICGOZN01 | 7229 | — | — |
| 312-288 | CHICGOZN01 | 7229 | — | Yes |
| 312-319 | CHICGOZN01 | 7229 | 2017-04-28 | Yes |
| 312-327 | CHICGOZN01 | 7229 | — | — |
| 312-377 | CHICGOZN01 | 7229 | — | — |
| 312-470 | CHICGOZN01 | 7229 | — | Yes |
| 312-471 | CHICGOZN01 | 7229 | 2015-06-26 | Yes |
| 312-486 | CHICGOZN01 | 7229 | 2004-04-23 | Yes |
| 312-517 | CHICGOZN01 | 7229 | 2015-02-09 | Yes |
| 312-525 | CHICGOZN01 | 7229 | 2002-03-20 | Yes |
| 312-585 | CHICGOZN01 | 7229 | 2013-04-16 | Yes |
| 312-594 | CHICGOZN01 | 7229 | 2008-11-06 | Yes |
| 312-601 | CHICGOZN01 | 7229 | — | — |
| 312-604 | CHICGOZN01 | 7229 | — | Yes |
| 312-628 | CHICGOZN01 | 7229 | — | Yes |
| 312-702 | CHICGOZN01 | 7229 | 2012-12-31 | Yes |
| 312-792 | CHICGOZN01 | 7229 | 2014-11-20 | Yes |
| 312-809 | CHICGOZN01 | 7229 | 2013-10-25 | Yes |
| 312-824 | CHICGOZN01 | 7229 | 2016-06-20 | Yes |
| 312-894 | CHICGOZN01 | 7229 | — | Yes |
| 312-897 | CHICGOZN01 | 7229 | 2015-03-23 | Yes |
| 312-973 | CHICGOZN01 | 7229 | 2014-02-19 | Yes |
| 312-999 | CHICGOZN01 | 7229 | 2010-08-20 | 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.