NumberResearchRecent thousands-block assignments
0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/19/2026
Most carrier growth happens here, not at the prefix level: under number pooling, carriers receive individual 1,000-number blocks (e.g. 626-470-0XXX) within already-assigned prefixes. Assignments are initial assignments — the current serving carrier of individual numbers may differ due to portability.
Most active assignees, all time — NPA 331
New assignments by month
Sep 2026
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2026-06-15 | 331-261-3XXX | 3000–3999 | Assigned | METROPCS, INC. | 5562 | LEMONT | IL |
| 2026-06-15 | 331-275-2XXX | 2000–2999 | Assigned | METROPCS, INC. | 5562 | BARTLETT | IL |
| 2026-06-15 | 331-344-3XXX | 3000–3999 | Assigned | METROPCS, INC. | 5562 | W CHICAGO | IL |
| 2026-06-15 | 331-346-3XXX | 3000–3999 | Assigned | METROPCS, INC. | 5562 | NAPERVILLE | IL |
| 2026-06-15 | 331-388-1XXX | 1000–1999 | Assigned | METROPCS, INC. | 5562 | SUGARGROVE | IL |
| 2026-06-15 | 331-462-3XXX | 3000–3999 | Assigned | METROPCS, INC. | 5562 | LOMBARD | IL |
| 2026-06-15 | 331-788-3XXX | 3000–3999 | Assigned | METROPCS, INC. | 5562 | GENEVA | IL |
| 2014-06-27 | 331-301-0XXX | 0000–0999 | Assigned | METROPCS, INC. | 5562 | AURORA | IL |
| 2014-06-27 | 331-301-8XXX | 8000–8999 | Assigned | METROPCS, INC. | 5562 | AURORA | IL |
| 2014-06-27 | 331-301-9XXX | 9000–9999 | Assigned | METROPCS, INC. | 5562 | AURORA | IL |
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.