NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026
The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| — | 605-272 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | GARY | SD |
| — | 605-345 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | WEBSTER | SD |
| — | 605-483 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | WENTWORTH | SD |
| — | 605-489 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | CHESTER | SD |
| — | 605-532 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | CLARK | SD |
| — | 605-542 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | ELKTON | SD |
| — | 605-586 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | NUNDA | SD |
| — | 605-623 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | REVILLO | SD |
| — | 605-625 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | BRYNTWLWLK | SD |
| — | 605-628 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | BRYNTWLWLK | SD |
| — | 605-629 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | WHITE | SD |
| — | 605-676 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | STOCKHOLM | SD |
| — | 605-693 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | BROOKINGSR | SD |
| — | 605-756 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | SOUTHSHORE | SD |
| — | 605-758 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | FLORENCE | SD |
| — | 605-783 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | HAYTI | SD |
| — | 605-784 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | BRADLEY | SD |
| — | 605-785 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | LAKENORDEN | SD |
| — | 605-793 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | CASTLEWOOD | SD |
| — | 605-794 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | TORONTO | SD |
| — | 605-795 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | GOODWIN | SD |
| — | 605-826 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | SINAI | SD |
| — | 605-832 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | ASTORIA | SD |
| — | 605-873 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | ESTELLINE | SD |
| — | 605-874 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | CLEAR LAKE | SD |
| — | 605-876 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | BRANDT | SD |
| — | 605-947 | not yet reported which blocks → | INTERSTATE TELECOM COOP, INC. - SD | 1651 | WAUBAY | SD |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.