NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026
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 |
|---|---|---|---|---|---|---|
| 2012-05-08 | 970-751 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | DELTA | CO |
| 2012-05-08 | 970-770 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | MONTROSE | CO |
| 2010-04-12 | 970-745 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | GRAND JCT | CO |
| 2010-04-12 | 970-767 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | FT COLLINS | CO |
| 2004-01-20 | 970-750 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | WALDEN | CO |
| 2004-01-20 | 970-755 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | RANGELY | CO |
| 2004-01-20 | 970-757 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | HAYDEN | CO |
| 2004-01-20 | 970-758 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | FRASER | CO |
| 2003-12-18 | 970-756 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | CRAIG | CO |
| — | 970-269 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | MAYBELL | CO |
| — | 970-326 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | CRAIG | CO |
| — | 970-537 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | KREMMLING | CO |
| — | 970-574 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | DINOSAUR | CO |
| — | 970-655 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | GRANBY | CO |
| — | 970-734 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | STEAMBOSPG | CO |
| — | 970-873 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | WALDEN | CO |
| — | 970-942 | not yet reported which blocks → | UNION TELEPHONE COMPANY | 013B | MEEKER | CO |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.