All assignees
798 prefixes in 312 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 312-600 | CHICGOZN01 | 224C | 2012-05-01 | Yes |
| 312-601 | CHICGOZN01 | 7229 | — | — |
| 312-602 | CHICGOZN01 | 6115 | — | — |
| 312-603 | CHICGOZN01 | 9329 | — | — |
| 312-604 | CHICGOZN01 | 7229 | — | Yes |
| 312-605 | CHICGOZN01 | 829J | 2012-08-06 | Yes |
| 312-606 | CHICGOZN01 | 9329 | — | — |
| 312-607 | CHICGOZN01 | 6534 | — | — |
| 312-608 | CHICGOZN01 | 6534 | — | — |
| 312-609 | CHICGOZN01 | 9329 | — | Yes |
| 312-610 | CHICGOZN01 | 6333 | 2012-08-06 | Yes |
| 312-611 | XXXXXXXXXX | MULT | — | — |
| 312-612 | CHICGOZN01 | 9329 | — | Yes |
| 312-613 | CHICGOZN01 | 6534 | — | — |
| 312-614 | CHICGOZN01 | 9329 | 2012-10-19 | Yes |
| 312-615 | WHEELING | 6534 | — | Yes |
| 312-616 | CHICGOZN01 | 9329 | — | — |
| 312-617 | CHICGOZN01 | 6529 | — | Yes |
| 312-618 | CHICGOZN01 | 6534 | — | — |
| 312-619 | CHICGOZN01 | 6529 | 2012-09-11 | Yes |
| 312-620 | CHICGOZN01 | 984E | 2012-08-15 | Yes |
| 312-621 | CHICGOZN01 | 9329 | — | — |
| 312-622 | CHICGOZN01 | 6534 | 2001-02-14 | Yes |
| 312-623 | CHICGOZN01 | 6534 | — | — |
| 312-624 | CHICGOZN01 | 8702 | — | Yes |
| 312-625 | CHICGOZN01 | 6115 | 2001-11-12 | Yes |
| 312-626 | CHICGOZN01 | 224C | 2008-02-04 | Yes |
| 312-627 | CHICGOZN01 | 9329 | — | Yes |
| 312-628 | CHICGOZN01 | 7229 | — | Yes |
| 312-629 | CHICGOZN01 | 9329 | — | — |
| 312-630 | CHICGOZN01 | 9329 | — | — |
| 312-631 | CHICGOZN01 | 508J | 2013-01-11 | Yes |
| 312-632 | CHICGOZN01 | 9329 | — | Yes |
| 312-633 | CHICGOZN01 | 9329 | — | — |
| 312-634 | CHICGOZN01 | 9329 | — | — |
| 312-635 | CHICGOZN01 | 6115 | — | Yes |
| 312-636 | CHICGOZN01 | 6333 | — | — |
| 312-637 | CHICGOZN01 | 6115 | — | Yes |
| 312-638 | CHICGOZN01 | 6115 | — | Yes |
| 312-639 | CHICGOZN01 | 6333 | 2017-10-19 | Yes |
| 312-640 | CHICGOZN01 | 9329 | — | — |
| 312-641 | CHICGOZN01 | 9329 | — | — |
| 312-642 | CHICGOZN01 | 9329 | — | — |
| 312-643 | CHICGOZN01 | 8702 | — | — |
| 312-644 | CHICGOZN01 | 9329 | — | — |
| 312-645 | CHICGOZN01 | 9329 | — | — |
| 312-646 | CHICGOZN01 | 6115 | — | Yes |
| 312-647 | CHICGOZN01 | 6529 | 2013-05-24 | Yes |
| 312-648 | CHICGOZN01 | 9329 | — | Yes |
| 312-649 | CHICGOZN01 | 9329 | — | — |
| 312-650 | CHICGOZN01 | 8702 | — | Yes |
| 312-651 | CHICGOZN01 | 9329 | — | Yes |
| 312-652 | CHICGOZN01 | 9329 | — | — |
| 312-653 | CHICGOZN01 | 9329 | — | — |
| 312-654 | CHICGOZN01 | 9329 | — | — |
| 312-655 | CHICGOZN01 | 9329 | — | — |
| 312-656 | CHICGOZN01 | 6529 | — | Yes |
| 312-657 | CHICGOZN01 | 6630 | — | — |
| 312-658 | CHICGOZN01 | 9329 | — | — |
| 312-659 | CHICGOZN01 | 6534 | — | — |
| 312-660 | CHICGOZN01 | 7136 | — | — |
| 312-661 | CHICGOZN01 | 9329 | — | Yes |
| 312-662 | CHICGOZN01 | 9329 | — | Yes |
| 312-663 | CHICGOZN01 | 9329 | — | — |
| 312-664 | CHICGOZN01 | 9329 | — | — |
| 312-665 | CHICGOZN01 | 7136 | — | — |
| 312-666 | CHICGOZN01 | 9329 | — | — |
| 312-667 | CHICGOZN01 | 063E | 2012-08-31 | Yes |
| 312-668 | CHICGOZN01 | 425J | 2019-05-28 | Yes |
| 312-669 | CHICGOZN01 | 9329 | — | Yes |
| 312-670 | CHICGOZN01 | 9329 | — | — |
| 312-671 | CHICGOZN01 | 6529 | — | Yes |
| 312-672 | CHICGOZN01 | 9329 | — | Yes |
| 312-673 | CHICGOZN01 | 460K | — | — |
| 312-674 | CHICGOZN01 | 9329 | — | Yes |
| 312-675 | CHICGOZN01 | 9329 | — | Yes |
| 312-676 | CHICGOZN01 | 460K | 2006-06-16 | Yes |
| 312-677 | CHICGOZN01 | 6630 | — | — |
| 312-678 | CHICGOZN01 | 6529 | 2013-07-25 | Yes |
| 312-679 | CHICGOZN01 | 671J | 2026-01-29 | Yes |
| 312-680 | CHICGOZN01 | 224C | 2022-04-29 | Yes |
| 312-681 | CHICGOZN01 | 9329 | — | Yes |
| 312-682 | CHICGOZN01 | 478J | 2020-05-14 | Yes |
| 312-683 | CHICGOZN01 | 9329 | — | Yes |
| 312-684 | CHICGOZN01 | 6529 | 2016-09-13 | Yes |
| 312-685 | CHICGOZN01 | 6529 | — | Yes |
| 312-686 | CHICGOZN01 | 063E | — | Yes |
| 312-687 | CHICGOZN01 | 6529 | 2016-09-13 | Yes |
| 312-688 | CHICGOZN01 | 6630 | — | — |
| 312-689 | CHICGOZN01 | 9748 | 2001-04-13 | — |
| 312-690 | CHICGOZN01 | 6115 | 2014-05-06 | Yes |
| 312-691 | CHICGOZN01 | 6795 | — | — |
| 312-692 | CHICGOZN01 | 9329 | — | Yes |
| 312-693 | CHICGOZN01 | 9329 | — | — |
| 312-694 | CHICGOZN01 | 9329 | — | Yes |
| 312-695 | CHICGOZN01 | 9329 | — | — |
| 312-696 | CHICGOZN01 | 9329 | — | Yes |
| 312-697 | CHICGOZN01 | 9329 | — | Yes |
| 312-698 | CHICGOZN01 | 6115 | 2001-08-23 | Yes |
| 312-699 | HINSDALE | 6534 | — | 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.