NumberResearchThousands-blocks in 831-435
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 831-435 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 831 blocks
Most active assignees, all time — NPA 831
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2008-06-24 | 831-435-0XXX | 0000–0999 | Assigned | METROPCS, INC. | 5562 | SANTA CRUZ | CA |
| 2024-12-16 | 831-435-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SANTA CRUZ | CA |
| — | 831-435-2XXX | 2000–2999 | Reserved | PACIFIC BELL | 9740 | SANTA CRUZ | CA |
| 2025-01-15 | 831-435-3XXX | 3000–3999 | Assigned | TERRA NOVA TELECOM INC. | 145J | SANTA CRUZ | CA |
| 2025-03-19 | 831-435-4XXX | 4000–4999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SANTA CRUZ | CA |
| 2003-09-26 | 831-435-5XXX | 5000–5999 | Assigned | METROPCS, INC. | 5562 | SANTA CRUZ | CA |
| 2012-08-21 | 831-435-6XXX | 6000–6999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2006-06-02 | 831-435-7XXX | 7000–7999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | SANTA CRUZ | CA |
| 2007-10-15 | 831-435-8XXX | 8000–8999 | Assigned | METROPCS, INC. | 5562 | SANTA CRUZ | CA |
| 2006-05-09 | 831-435-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SANTA CRUZ | CA |
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.