NumberResearchThousands-blocks in 623-233
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 623-233 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 623 blocks
Most active assignees, all time — NPA 623
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2017-11-10 | 623-233-0XXX | 0000–0999 | Assigned | ONVOY, LLC - AZ | 630E | PHOENIX | AZ |
| 2017-08-28 | 623-233-1XXX | 1000–1999 | Assigned | RE-INVENT TELECOM, LLC - AZ | 663G | PHOENIX | AZ |
| 2016-11-22 | 623-233-2XXX | 2000–2999 | Assigned | BANDWIDTH.COM CLEC, LLC - AZ | 587F | PHOENIX | AZ |
| 2016-11-22 | 623-233-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - AZ | 587F | PHOENIX | AZ |
| 2016-11-22 | 623-233-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - AZ | 587F | PHOENIX | AZ |
| 2017-01-20 | 623-233-5XXX | 5000–5999 | Assigned | COMCAST IP PHONE, LLC | 318J | PHOENIX | AZ |
| 2017-01-20 | 623-233-6XXX | 6000–6999 | Assigned | COMCAST IP PHONE, LLC | 318J | PHOENIX | AZ |
| 2017-01-12 | 623-233-7XXX | 7000–7999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | PHOENIX | AZ |
| 2017-02-15 | 623-233-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | PHOENIX | AZ |
| 2017-03-10 | 623-233-9XXX | 9000–9999 | Assigned | METROPCS, INC. | 5562 | PHOENIX | 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.