NumberResearchThousands-blocks in 830-538
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 830-538 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 830 blocks
Most active assignees, all time — NPA 830
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2016-07-11 | 830-538-0XXX | 0000–0999 | Assigned | ONVOY, LLC - TX | 903C | CASTROVL | TX |
| — | 830-538-1XXX | 1000–1999 | Reserved | SOUTHWESTERN BELL | 9533 | CASTROVL | TX |
| — | 830-538-2XXX | 2000–2999 | Reserved | SOUTHWESTERN BELL | 9533 | CASTROVL | TX |
| — | 830-538-3XXX | 3000–3999 | Reserved | SOUTHWESTERN BELL | 9533 | CASTROVL | TX |
| 2009-12-31 | 830-538-4XXX | 4000–4999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | CASTROVL | TX |
| 2011-03-01 | 830-538-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | CASTROVL | TX |
| — | 830-538-6XXX | 6000–6999 | Reserved | SOUTHWESTERN BELL | 9533 | CASTROVL | TX |
| 2016-10-19 | 830-538-7XXX | 7000–7999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | CASTROVL | TX |
| 2012-06-28 | 830-538-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | CASTROVL | TX |
| — | 830-538-9XXX | 9000–9999 | Reserved | SOUTHWESTERN BELL | 9533 | CASTROVL | TX |
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.