NumberResearchThousands-blocks in 530-531
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 530-531 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 530 blocks
Most active assignees, all time — NPA 530
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 |
|---|---|---|---|---|---|---|---|
| 2014-03-07 | 530-531-0XXX | 0000–0999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BIGGS | CA |
| — | 530-531-1XXX | 1000–1999 | Reserved | IP HORIZON LLC | 515J | BIGGS | CA |
| — | 530-531-2XXX | 2000–2999 | Reserved | IP HORIZON LLC | 515J | BIGGS | CA |
| 2011-03-11 | 530-531-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | BIGGS | CA |
| 2019-04-17 | 530-531-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | BIGGS | CA |
| 2004-09-07 | 530-531-5XXX | 5000–5999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BIGGS | CA |
| 2024-12-16 | 530-531-6XXX | 6000–6999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | BIGGS | CA |
| 2015-10-09 | 530-531-7XXX | 7000–7999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | BIGGS | CA |
| 2017-04-13 | 530-531-8XXX | 8000–8999 | Assigned | ONVOY, LLC - CA | 649C | BIGGS | CA |
| 2016-02-10 | 530-531-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | BIGGS | CA |
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.