NumberResearchThousands-blocks in 518-503
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 518-503 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
Jul 2026
Jun 2026
May 2026
Apr 2026
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Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2006-10-13 | 518-503-0XXX | 0000–0999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - NY | 4006 | TICONDROGA | NY |
| 2007-07-26 | 518-503-1XXX | 1000–1999 | Assigned | PAETEC ITEL, LLC | 829J | TICONDROGA | NY |
| 2008-04-17 | 518-503-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - NY | 4006 | TICONDROGA | NY |
| 2012-12-31 | 518-503-3XXX | 3000–3999 | Assigned | ONVOY, LLC- NY | 384C | TICONDROGA | NY |
| 2012-03-12 | 518-503-4XXX | 4000–4999 | Assigned | ONVOY, LLC- NY | 384C | TICONDROGA | NY |
| 2005-06-01 | 518-503-5XXX | 5000–5999 | Assigned | TWC IP ENABLED SERVICES, LLC | 793K | TICONDROGA | NY |
| 2015-01-28 | 518-503-6XXX | 6000–6999 | Assigned | BANDWIDTH.COM CLEC, LLC - NY | 997E | TICONDROGA | NY |
| 2016-08-02 | 518-503-7XXX | 7000–7999 | Assigned | HD CARRIER LLC | 321J | TICONDROGA | NY |
| — | 518-503-8XXX | 8000–8999 | Reserved | TC SYSTEMS, INC. - NY | 7140 | TICONDROGA | NY |
| 2015-12-16 | 518-503-9XXX | 9000–9999 | Assigned | PEERLESS NETWORK OF NEW YORK, LLC - NY | 155E | TICONDROGA | 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.