NumberResearchThousands-blocks in 531-288
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 531-288 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 531 blocks
Most active assignees, all time — NPA 531
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 |
|---|---|---|---|---|---|---|---|
| 2025-05-29 | 531-288-0XXX | 0000–0999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | MADISON | NE |
| 2025-11-05 | 531-288-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | MADISON | NE |
| 2025-06-24 | 531-288-2XXX | 2000–2999 | Assigned | TERRA NOVA TELECOM INC. | 145J | MADISON | NE |
| — | 531-288-3XXX | 3000–3999 | Available | MADISON | NE | ||
| — | 531-288-4XXX | 4000–4999 | Available | MADISON | NE | ||
| — | 531-288-5XXX | 5000–5999 | Available | MADISON | NE | ||
| 2023-01-23 | 531-288-6XXX | 6000–6999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - NE | 7144 | MADISON | NE |
| 2024-10-11 | 531-288-7XXX | 7000–7999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | MADISON | NE |
| 2024-03-22 | 531-288-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | MADISON | NE |
| 2022-08-04 | 531-288-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | MADISON | NE |
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.