All assignees
798 prefixes in 312 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 312-800 | CHICGOZN01 | 063E | 2012-11-20 | Yes |
| 312-801 | CHICGOZN01 | 551G | 2013-04-29 | Yes |
| 312-802 | CHICGOZN01 | 6333 | — | — |
| 312-803 | CHICGOZN01 | 7196 | — | — |
| 312-804 | CHICGOZN01 | 6529 | 2002-01-23 | — |
| 312-805 | CHICGOZN01 | 6333 | — | — |
| 312-806 | CHICGOZN01 | 6534 | — | — |
| 312-807 | CHICGOZN01 | 9329 | — | — |
| 312-808 | CHICGOZN01 | 9329 | — | — |
| 312-809 | CHICGOZN01 | 7229 | 2013-10-25 | Yes |
| 312-810 | CHICGOZN01 | 6534 | — | — |
| 312-811 | XXXXXXXXXX | MULT | — | — |
| 312-812 | CHICGOZN01 | 9329 | — | — |
| 312-813 | CHICGOZN01 | 6534 | — | — |
| 312-814 | CHICGOZN01 | 9329 | — | — |
| 312-815 | CHICGOZN01 | 996H | 2018-05-07 | Yes |
| 312-816 | HINSDALE | 6534 | — | Yes |
| 312-817 | CHICGOZN01 | 9329 | — | — |
| 312-818 | CHICGOZN01 | 6529 | 2013-08-19 | Yes |
| 312-819 | CHICGOZN01 | 9329 | — | — |
| 312-820 | CHICGOZN01 | 224C | 2020-01-08 | Yes |
| 312-821 | CHICGOZN01 | 7196 | — | Yes |
| 312-822 | CHICGOZN01 | 9329 | — | — |
| 312-823 | CHICGOZN01 | 9329 | — | Yes |
| 312-824 | CHICGOZN01 | 7229 | 2016-06-20 | Yes |
| 312-825 | CHICGOZN01 | 6529 | 2016-03-17 | Yes |
| 312-826 | CHICGOZN01 | 6529 | 2016-06-17 | Yes |
| 312-827 | CHICGOZN01 | 9329 | — | — |
| 312-828 | CHICGOZN01 | 9329 | — | — |
| 312-829 | CHICGOZN01 | 9329 | — | — |
| 312-831 | CHICGOZN01 | 9329 | — | — |
| 312-832 | CHICGOZN01 | 9329 | — | — |
| 312-833 | CHICGOZN01 | 6333 | — | — |
| 312-834 | CHICGOZN01 | 9329 | — | Yes |
| 312-835 | CHICGOZN01 | 6333 | — | — |
| 312-836 | CHICGOZN01 | 9329 | — | — |
| 312-837 | CHICGOZN01 | 318J | 2015-09-03 | Yes |
| 312-838 | CHICGOZN01 | 6529 | 2016-01-11 | Yes |
| 312-839 | CHICGOZN01 | 9748 | 2001-04-13 | — |
| 312-840 | CHICGOZN01 | 9329 | — | — |
| 312-841 | CHICGOZN01 | 6534 | — | Yes |
| 312-842 | CHICGOZN01 | 9329 | — | — |
| 312-843 | CHICGOZN01 | 7136 | 2014-03-12 | Yes |
| 312-844 | HINSDALE | 6534 | — | Yes |
| 312-845 | CHICGOZN01 | 9329 | — | — |
| 312-846 | CHICGOZN01 | 9329 | — | Yes |
| 312-847 | CHICGOZN01 | 224C | 2019-06-28 | Yes |
| 312-848 | CHICGOZN01 | 6333 | — | — |
| 312-849 | CHICGOZN01 | 9329 | — | — |
| 312-850 | CHICGOZN01 | 9329 | — | — |
| 312-851 | CHICGOZN01 | 6630 | — | — |
| 312-852 | CHICGOZN01 | 6534 | — | Yes |
| 312-853 | CHICGOZN01 | 9329 | — | — |
| 312-854 | CHICGOZN01 | 8702 | — | Yes |
| 312-855 | CHICGOZN01 | 9329 | — | — |
| 312-856 | CHICGOZN01 | 9329 | — | Yes |
| 312-857 | CHICGOZN01 | 9329 | — | Yes |
| 312-858 | CHICGOZN01 | 6115 | 2015-12-21 | Yes |
| 312-859 | CHICGOZN01 | 6333 | — | — |
| 312-860 | CHICGOZN01 | 6534 | — | — |
| 312-861 | CHICGOZN01 | 9329 | — | — |
| 312-862 | CHICGOZN01 | 9329 | 2006-01-25 | Yes |
| 312-863 | CHICGOZN01 | 829J | 2001-04-10 | Yes |
| 312-864 | CHICGOZN01 | 9329 | — | — |
| 312-865 | WHEELING | 6534 | — | Yes |
| 312-866 | CHICGOZN01 | 6529 | 2014-08-22 | Yes |
| 312-867 | CHICGOZN01 | 9329 | — | — |
| 312-868 | CHICGOZN01 | 984E | 2015-12-04 | Yes |
| 312-869 | CHICGOZN01 | 9329 | — | Yes |
| 312-870 | CHICGOZN01 | 460K | — | Yes |
| 312-871 | CHICGOZN01 | 6529 | 2015-08-28 | Yes |
| 312-872 | CHICGOZN01 | 6115 | 2018-07-12 | Yes |
| 312-873 | CHICGOZN01 | 7196 | — | — |
| 312-874 | CHICGOZN01 | 6529 | 2015-05-22 | Yes |
| 312-875 | CHICGOZN01 | 9329 | — | — |
| 312-876 | CHICGOZN01 | 9329 | — | — |
| 312-877 | CHICGOZN01 | 516C | 2014-08-12 | Yes |
| 312-878 | CHICGOZN01 | 063E | 2008-02-04 | Yes |
| 312-879 | CHICGOZN01 | 9329 | — | Yes |
| 312-880 | CHICGOZN01 | 9329 | — | Yes |
| 312-881 | CHICGOZN01 | 829J | 2001-04-10 | Yes |
| 312-882 | CHICGOZN01 | 6333 | — | — |
| 312-883 | CHICGOZN01 | 984E | 2014-11-12 | Yes |
| 312-884 | CHICGOZN01 | 829J | 2001-04-10 | Yes |
| 312-885 | CHICGOZN01 | 6529 | 2015-09-22 | Yes |
| 312-886 | CHICGOZN01 | 9329 | — | — |
| 312-887 | CHICGOZN01 | 9329 | — | Yes |
| 312-888 | CHICGOZN01 | 6534 | 2012-01-13 | Yes |
| 312-889 | CHICGOZN01 | 7136 | 2015-06-25 | Yes |
| 312-890 | CHICGOZN01 | 6529 | — | Yes |
| 312-891 | CHICGOZN01 | 6630 | — | — |
| 312-892 | CHICGOZN01 | 7136 | — | Yes |
| 312-893 | CHICGOZN01 | 6115 | — | Yes |
| 312-894 | CHICGOZN01 | 7229 | — | Yes |
| 312-895 | CHICGOZN01 | 6115 | — | — |
| 312-896 | CHICGOZN01 | 6115 | — | — |
| 312-897 | CHICGOZN01 | 7229 | 2015-03-23 | Yes |
| 312-898 | CHICGOZN01 | 6333 | — | — |
| 312-899 | CHICGOZN01 | 9329 | — | Yes |
| 312-900 | CHICGOZN01 | 965H | 2019-01-18 | 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.