NumberResearchThousands-blocks in 603-290
This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/20/2026
The ten 1,000-number thousand-blocks inside prefix 603-290 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 603 blocks
Most active assignees, all time — NPA 603
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
Mar 2026
Feb 2026
Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2008-10-20 | 603-290-0XXX | 0000–0999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | CONCORD | NH |
| 2008-10-20 | 603-290-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | CONCORD | NH |
| 2008-10-20 | 603-290-2XXX | 2000–2999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | CONCORD | NH |
| 2008-08-20 | 603-290-3XXX | 3000–3999 | Assigned | OMNIPOINT MIAMI E LICENSE, LLC | 6889 | CONCORD | NH |
| 2009-10-30 | 603-290-4XXX | 4000–4999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | CONCORD | NH |
| 2010-09-03 | 603-290-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - NH | 4017 | CONCORD | NH |
| 2023-10-02 | 603-290-6XXX | 6000–6999 | Assigned | BOOST SUBSCRIBERCO L.L.C. | 490J | CONCORD | NH |
| — | 603-290-7XXX | 7000–7999 | Reserved | UNITED STATES CELLULAR - NH | 6290 | CONCORD | NH |
| — | 603-290-8XXX | 8000–8999 | Reserved | UNITED STATES CELLULAR - NH | 6290 | CONCORD | NH |
| 2016-11-10 | 603-290-9XXX | 9000–9999 | Assigned | OMNIPOINT MIAMI E LICENSE, LLC | 6889 | CONCORD | NH |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.