NumberResearchThousands-blocks in 203-513
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 203-513 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 203 blocks
Most active assignees, all time — NPA 203
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 |
|---|---|---|---|---|---|---|---|
| 2006-02-07 | 203-513-0XXX | 0000–0999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | HUNTINGTON | CT |
| 2004-02-11 | 203-513-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | HUNTINGTON | CT |
| 2006-11-09 | 203-513-2XXX | 2000–2999 | Assigned | COMCAST IP PHONE, LLC | 318J | HUNTINGTON | CT |
| 2003-06-26 | 203-513-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CT | 4800 | HUNTINGTON | CT |
| 2010-02-02 | 203-513-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - CT | 199F | HUNTINGTON | CT |
| 2007-04-26 | 203-513-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CT | 4800 | HUNTINGTON | CT |
| — | 203-513-6XXX | 6000–6999 | Reserved | AT&T - LOCAL | 7421 | HUNTINGTON | CT |
| 2006-06-20 | 203-513-7XXX | 7000–7999 | Assigned | SOUTHERN NEW ENGLAND TELCO DBA FRONTIER COMM OF CT | 9147 | HUNTINGTON | CT |
| 2008-08-27 | 203-513-8XXX | 8000–8999 | Assigned | COMCAST IP PHONE, LLC | 318J | HUNTINGTON | CT |
| 2008-10-30 | 203-513-9XXX | 9000–9999 | Assigned | BANDWIDTH.COM CLEC, LLC - CT | 199F | HUNTINGTON | CT |
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.