NumberResearchThousands-blocks in 831-628
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 831-628 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
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2021-09-07 | 831-628-0XXX | 0000–0999 | Assigned | TERRA NOVA TELECOM INC. | 145J | TRES PINOS | CA |
| — | 831-628-1XXX | 1000–1999 | Reserved | PACIFIC BELL | 9740 | TRES PINOS | CA |
| — | 831-628-2XXX | 2000–2999 | Available | TRES PINOS | CA | ||
| — | 831-628-3XXX | 3000–3999 | Reserved | PACIFIC BELL | 9740 | TRES PINOS | CA |
| — | 831-628-4XXX | 4000–4999 | Available | TRES PINOS | CA | ||
| 2011-09-14 | 831-628-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | TRES PINOS | CA |
| — | 831-628-6XXX | 6000–6999 | Available | TRES PINOS | CA | ||
| 2021-06-09 | 831-628-7XXX | 7000–7999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | TRES PINOS | CA |
| 2016-08-26 | 831-628-8XXX | 8000–8999 | Assigned | CHARTER IP ENABLED SERVICES, LLC | 792K | TRES PINOS | CA |
| 2022-10-05 | 831-628-9XXX | 9000–9999 | Assigned | TERRA NOVA TELECOM INC. | 145J | TRES PINOS | 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.