All assignees
798 prefixes in 312 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 312-700 | — | — | ||
| 312-701 | CHICGOZN01 | 9329 | — | Yes |
| 312-702 | CHICGOZN01 | 7229 | 2012-12-31 | Yes |
| 312-703 | CHICGOZN01 | 9329 | — | — |
| 312-704 | CHICGOZN01 | 9329 | — | — |
| 312-705 | CHICGOZN01 | 7136 | — | — |
| 312-706 | CHICGOZN01 | 7136 | — | — |
| 312-707 | CHICGOZN01 | 9329 | — | — |
| 312-708 | CHICGOZN01 | 624H | 2024-02-20 | Yes |
| 312-709 | CHICGOZN01 | 6529 | 2013-05-24 | Yes |
| 312-710 | CHICGOZN01 | 9329 | — | — |
| 312-711 | XXXXXXXXXX | MULT | — | — |
| 312-712 | CHICGOZN01 | 9329 | — | — |
| 312-713 | CHICGOZN01 | 9748 | 2001-04-16 | — |
| 312-714 | CHICGOZN01 | 9329 | — | Yes |
| 312-715 | CHICGOZN01 | 9329 | — | Yes |
| 312-716 | CHICGOZN01 | 9329 | — | — |
| 312-717 | LA GRANGE | 6630 | — | — |
| 312-718 | CHICGOZN01 | 6333 | — | — |
| 312-719 | CHICGOZN01 | 6529 | — | Yes |
| 312-720 | CHICGOZN01 | 6333 | — | — |
| 312-721 | CHICGOZN01 | 6529 | 2013-10-22 | Yes |
| 312-722 | CHICGOZN01 | 829J | 2015-06-01 | Yes |
| 312-723 | CHICGOZN01 | 6534 | 2016-11-28 | Yes |
| 312-724 | CHICGOZN01 | 984E | 2013-02-07 | Yes |
| 312-725 | CHICGOZN01 | 984E | 2008-10-08 | Yes |
| 312-726 | CHICGOZN01 | 9329 | — | — |
| 312-727 | CHICGOZN01 | 9329 | — | — |
| 312-728 | CHICGOZN01 | 6333 | 2017-10-19 | Yes |
| 312-729 | CHICGOZN01 | 9329 | — | — |
| 312-730 | CHICGOZN01 | 7421 | — | Yes |
| 312-731 | CHICGOZN01 | 6529 | — | Yes |
| 312-732 | CHICGOZN01 | 9329 | — | — |
| 312-733 | CHICGOZN01 | 9329 | — | — |
| 312-734 | CHICGOZN01 | 7136 | 2015-09-17 | Yes |
| 312-735 | CHICGOZN04 | 6529 | 2001-07-06 | Yes |
| 312-736 | CHICGOZN01 | 7136 | 2017-10-20 | Yes |
| 312-737 | CHICGOZN01 | 9329 | — | — |
| 312-738 | CHICGOZN01 | 9329 | — | — |
| 312-739 | CHICGOZN01 | 9329 | — | — |
| 312-740 | CHICGOZN01 | 9748 | 2001-04-13 | — |
| 312-741 | CHICGOZN01 | 829J | 2017-10-20 | Yes |
| 312-742 | CHICGOZN01 | 9329 | — | — |
| 312-743 | CHICGOZN01 | 9329 | 2001-11-15 | Yes |
| 312-744 | CHICGOZN01 | 9329 | — | — |
| 312-745 | CHICGOZN01 | 9329 | — | — |
| 312-746 | CHICGOZN01 | 9329 | — | — |
| 312-747 | CHICGOZN01 | 9329 | — | — |
| 312-748 | CHICGOZN01 | 224C | 2023-05-22 | Yes |
| 312-749 | HINSDALE | 6534 | — | Yes |
| 312-750 | CHICGOZN01 | 9329 | — | — |
| 312-751 | CHICGOZN01 | 9329 | — | — |
| 312-752 | CHICGOZN01 | 6115 | 2002-04-19 | Yes |
| 312-753 | CHICGOZN01 | 8702 | — | Yes |
| 312-754 | CHICGOZN01 | 138G | 2013-02-26 | Yes |
| 312-755 | CHICGOZN01 | 9329 | — | — |
| 312-756 | CHICGOZN01 | 9329 | — | Yes |
| 312-757 | CHICGOZN01 | 984E | — | Yes |
| 312-758 | CHICGOZN01 | 6333 | — | — |
| 312-759 | CHICGOZN01 | 9329 | — | Yes |
| 312-760 | CHICGOZN01 | 9748 | 2001-04-13 | — |
| 312-761 | CHICGOZN01 | 148J | 2018-05-25 | Yes |
| 312-762 | CHICGOZN01 | 9329 | — | — |
| 312-763 | CHICGOZN01 | 318J | 2014-05-12 | Yes |
| 312-764 | CHICGOZN01 | 7136 | 2016-10-20 | Yes |
| 312-765 | CHICGOZN01 | 9329 | — | Yes |
| 312-766 | CHICGOZN01 | 063E | 2016-10-17 | Yes |
| 312-767 | CHICGOZN01 | 984E | 2015-04-16 | Yes |
| 312-768 | CHICGOZN01 | 7136 | — | Yes |
| 312-769 | CHICGOZN01 | 6795 | — | — |
| 312-770 | CHICGOZN01 | 9329 | — | Yes |
| 312-771 | CHICGOZN01 | 6333 | — | — |
| 312-772 | CHICGOZN01 | 6534 | 2008-08-18 | Yes |
| 312-773 | CHICGOZN01 | 624H | 2023-05-19 | Yes |
| 312-774 | CHICGOZN01 | 6529 | 2013-08-19 | Yes |
| 312-775 | CHICGOZN01 | 9329 | — | Yes |
| 312-776 | CHICGOZN01 | 6529 | 2019-01-30 | Yes |
| 312-777 | CHICGOZN01 | 7136 | — | Yes |
| 312-778 | CHICGOZN01 | 224C | 2015-05-08 | Yes |
| 312-779 | CHICGOZN01 | 224C | 2019-05-13 | Yes |
| 312-780 | CHICGOZN01 | 7196 | — | Yes |
| 312-781 | CHICGOZN01 | 9329 | — | — |
| 312-782 | CHICGOZN01 | 9329 | — | — |
| 312-783 | CHICGOZN01 | 6534 | 2016-08-08 | Yes |
| 312-784 | CHICGOZN01 | 460K | 2007-07-12 | Yes |
| 312-785 | CHICGOZN01 | 6534 | 2014-08-19 | Yes |
| 312-786 | CHICGOZN01 | 9329 | — | — |
| 312-787 | CHICGOZN01 | 9329 | — | — |
| 312-788 | CHICGOZN01 | 9329 | — | Yes |
| 312-789 | CHICGOZN01 | 9329 | — | Yes |
| 312-790 | CHICGOZN01 | 9329 | — | — |
| 312-791 | CHICGOZN01 | 9329 | — | Yes |
| 312-792 | CHICGOZN01 | 7229 | 2014-11-20 | Yes |
| 312-793 | CHICGOZN01 | 9329 | — | — |
| 312-794 | CHICGOZN01 | 8702 | — | Yes |
| 312-795 | CHICGOZN01 | 9329 | — | — |
| 312-796 | CHICGOZN01 | 063E | 2016-07-26 | Yes |
| 312-797 | CHICGOZN01 | 9329 | — | — |
| 312-798 | CHICGOZN01 | 9329 | — | Yes |
| 312-799 | CHICGOZN01 | 9329 | — | 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.