NumberResearchThousands-blocks in 518-531
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 518-531 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 518 blocks
Most active assignees, all time — NPA 518
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 |
|---|---|---|---|---|---|---|---|
| 2017-04-14 | 518-531-0XXX | 0000–0999 | Assigned | TELNYX LLC | 073H | GREENWICH | NY |
| 2018-08-16 | 518-531-1XXX | 1000–1999 | Assigned | BLUEBIRD COMMUNICATIONS, LLC - NY | 970H | GREENWICH | NY |
| 2006-09-06 | 518-531-2XXX | 2000–2999 | Assigned | RINGSQUARED TELECOM LLC | 8249 | GREENWICH | NY |
| 2006-10-13 | 518-531-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - NY | 4006 | GREENWICH | NY |
| 2005-09-15 | 518-531-4XXX | 4000–4999 | Assigned | TWC IP ENABLED SERVICES, LLC | 793K | GREENWICH | NY |
| — | 518-531-5XXX | 5000–5999 | Available | GREENWICH | NY | ||
| 2010-03-04 | 518-531-6XXX | 6000–6999 | Assigned | BANDWIDTH.COM CLEC, LLC - NY | 997E | GREENWICH | NY |
| 2016-08-23 | 518-531-7XXX | 7000–7999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | GREENWICH | NY |
| 2009-12-03 | 518-531-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - NY | 997E | GREENWICH | NY |
| — | 518-531-9XXX | 9000–9999 | Reserved | TC SYSTEMS, INC. - NY | 7140 | GREENWICH | NY |
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.