NumberResearchThousands-blocks in 350-257
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 350-257 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 350 blocks
Most active assignees, last 30 days — NPA 350
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
Mar 2026
Feb 2026
Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2026-05-06 | 350-257-0XXX | 0000–0999 | Assigned | ONVOY, LLC - CA | 649C | RIPON | CA |
| — | 350-257-1XXX | 1000–1999 | Available | RIPON | CA | ||
| — | 350-257-2XXX | 2000–2999 | Available | RIPON | CA | ||
| — | 350-257-3XXX | 3000–3999 | Available | RIPON | CA | ||
| — | 350-257-4XXX | 4000–4999 | Available | RIPON | CA | ||
| — | 350-257-5XXX | 5000–5999 | Available | RIPON | CA | ||
| — | 350-257-6XXX | 6000–6999 | Available | RIPON | CA | ||
| 2026-09-01 | 350-257-7XXX | 7000–7999 | Assigned | EXIANT COMMUNICATIONS LLC | 114J | RIPON | CA |
| — | 350-257-8XXX | 8000–8999 | Available | RIPON | CA | ||
| 2026-04-22 | 350-257-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | RIPON | 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.