NumberResearchThousands-blocks in 928-583
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 928-583 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 928 blocks
Most active assignees, all time — NPA 928
New assignments by month
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 928-583-0XXX | 0000–0999 | Reserved | QWEST CORPORATION | 9636 | PRESCOTT | AZ |
| — | 928-583-1XXX | 1000–1999 | Reserved | QWEST CORPORATION | 9636 | PRESCOTT | AZ |
| 2008-01-29 | 928-583-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | PRESCOTT | AZ |
| 2009-01-19 | 928-583-3XXX | 3000–3999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | PRESCOTT | AZ |
| 2009-09-03 | 928-583-4XXX | 4000–4999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ | 6572 | PRESCOTT | AZ |
| — | 928-583-5XXX | 5000–5999 | Reserved | QWEST CORPORATION | 9636 | PRESCOTT | AZ |
| — | 928-583-6XXX | 6000–6999 | Reserved | QWEST CORPORATION | 9636 | PRESCOTT | AZ |
| 2007-04-25 | 928-583-7XXX | 7000–7999 | Assigned | ONVOY, LLC - AZ | 630E | PRESCOTT | AZ |
| 2009-04-13 | 928-583-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | PRESCOTT | AZ |
| 2016-03-30 | 928-583-9XXX | 9000–9999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - AZ | 3285 | PRESCOTT | AZ |
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.