NumberResearchThousands-blocks in 251-299
This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/19/2026
The ten 1,000-number thousand-blocks inside prefix 251-299 and who was initially assigned each. Under pooling these blocks often belong to different carriers — the single prefix-level “assignee” is usually just the pool / code holder, not who holds the numbers. ← all 251 blocks
Most active assignees, all time — NPA 251
New assignments by month
Sep 2026
Aug 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2016-02-10 | 251-299-0XXX | 0000–0999 | Assigned | ONVOY, LLC - AL | 604E | MT VERNON | AL |
| 2010-05-21 | 251-299-1XXX | 1000–1999 | Assigned | MCC TELEPHONY OF THE SOUTH, LLC - AL | 773F | MT VERNON | AL |
| 2014-06-04 | 251-299-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - AL | 5255 | MT VERNON | AL |
| 2013-04-12 | 251-299-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - AL | 7221 | MT VERNON | AL |
| 2019-05-09 | 251-299-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - AL | 072F | MT VERNON | AL |
| 2020-04-08 | 251-299-5XXX | 5000–5999 | Assigned | TELNYX LLC | 073H | MT VERNON | AL |
| 2019-03-14 | 251-299-6XXX | 6000–6999 | Assigned | ONVOY, LLC - AL | 604E | MT VERNON | AL |
| 2014-04-11 | 251-299-7XXX | 7000–7999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | MT VERNON | AL |
| 2016-02-10 | 251-299-8XXX | 8000–8999 | Assigned | ONVOY, LLC - AL | 604E | MT VERNON | AL |
| 2019-03-14 | 251-299-9XXX | 9000–9999 | Assigned | ONVOY, LLC - AL | 604E | MT VERNON | AL |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.