NumberResearchThousands-blocks in 253-737
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 253-737 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 253 blocks
Most active assignees, all time — NPA 253
New assignments by month
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2006-11-03 | 253-737-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | AUBURN | WA |
| — | 253-737-1XXX | 1000–1999 | Reserved | LEVEL 3 TELECOM OF WASHINGTON, LLC - WA | 7455 | AUBURN | WA |
| — | 253-737-2XXX | 2000–2999 | Reserved | LEVEL 3 TELECOM OF WASHINGTON, LLC - WA | 7455 | AUBURN | WA |
| 2007-02-14 | 253-737-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | AUBURN | WA |
| 2006-07-12 | 253-737-4XXX | 4000–4999 | Assigned | COMCAST IP PHONE, LLC | 318J | AUBURN | WA |
| 2006-07-12 | 253-737-5XXX | 5000–5999 | Assigned | COMCAST IP PHONE, LLC | 318J | AUBURN | WA |
| 2007-09-06 | 253-737-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | AUBURN | WA |
| 2006-09-26 | 253-737-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | AUBURN | WA |
| 2006-03-02 | 253-737-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | AUBURN | WA |
| 2006-11-03 | 253-737-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | AUBURN | WA |
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.