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 |
|---|---|---|---|---|---|---|
| 2006-02-01 | 517-920 | 0–9 XXXall 10 · 4 holders which blocks → | TELNET WORLDWIDE, INC. | 817J | ADRIAN | MI |
| 2004-12-06 | 517-330 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | LITCHFIELD | MI |
| 2002-04-22 | 517-621 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | MUNITH | MI |
| 2002-04-22 | 517-634 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | FITCHBURG | MI |
| 2002-04-22 | 517-653 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | BURLINGTON | MI |
| 2002-04-22 | 517-671 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | TEKONSHA | MI |
| 2002-04-22 | 517-710 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | STOCKBDG | MI |
| 2002-04-22 | 517-872 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | RIVES JCT | MI |
| 2002-03-27 | 517-631 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | WEBBERVL | MI |
| 2002-03-27 | 517-658 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | READING | MI |
| 2002-03-27 | 517-716 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | PARMA | MI |
| 2002-03-27 | 517-724 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | HOMER | MI |
| 2002-01-25 | 517-659 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | ADDISON | MI |
| 2001-12-05 | 517-717 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | WILLIAMSTN | MI |
| 2001-12-05 | 517-766 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | ONONDAGA | MI |
| 2001-11-13 | 517-519 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | HUDSON | MI |
| 2001-11-13 | 517-654 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | ALBION | MI |
| 2001-11-13 | 517-689 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | HILLSDALE | MI |
| 2001-11-13 | 517-753 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | COLDWATER | MI |
| 2001-11-13 | 517-772 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | DANSVILLE | MI |
| 2001-11-13 | 517-848 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | PORTLAND | MI |
| 2001-11-13 | 517-916 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | JONESVILLE | MI |
| 2001-11-01 | 517-727 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | CHARLOTTE | MI |
| 2001-02-28 | 517-905 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | JACKSON | MI |
| — | 517-207 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | ADRIAN | MI |
| — | 517-809 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | TECUMSEH | MI |
| — | 517-813 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | BLISSFIELD | MI |
| — | 517-913 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | LANSING | MI |
| — | 517-947 | not yet reported which blocks → | TELNET WORLDWIDE, INC. | 817J | HOWELL | MI |
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.