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 657
New assignments by month
Sep 2026
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2016-09-21 | 657-295-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | ANAHEIM | CA |
| 2016-09-21 | 657-315-9XXX | 9000–9999 | Assigned | AT&T ENTERPRISES, LLC | 516C | PLACENTIA | CA |
| 2016-09-21 | 657-346-0XXX | 0000–0999 | Assigned | AT&T ENTERPRISES, LLC | 516C | SANTA ANA | CA |
| 2016-09-14 | 657-377-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | GARDEN GRV | CA |
| 2016-07-15 | 657-445-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | FULLERTON | CA |
| 2016-06-17 | 657-337-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | CYPRESS | CA |
| 2015-05-13 | 657-266-0XXX | 0000–0999 | Assigned | AT&T ENTERPRISES, LLC | 516C | SANTA ANA | CA |
| 2014-09-17 | 657-529-1XXX | 1000–1999 | Assigned | AT&T ENTERPRISES, LLC | 516C | BUENA PARK | CA |
| 2014-09-04 | 657-230-9XXX | 9000–9999 | Assigned | AT&T ENTERPRISES, LLC | 516C | ANAHEIM | CA |
| 2014-08-21 | 657-236-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | ORANGE | CA |
| 2014-07-30 | 657-245-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | SANTA ANA | CA |
| 2014-01-24 | 657-233-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | GARDEN GRV | CA |
| 2013-12-31 | 657-231-6XXX | 6000–6999 | Assigned | AT&T ENTERPRISES, LLC | 516C | SANTA ANA | CA |
| 2011-09-20 | 657-444-2XXX | 2000–2999 | Assigned | AT&T ENTERPRISES, LLC | 516C | PLACENTIA | CA |
| 2011-09-01 | 657-217-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | FULLERTON | CA |
| 2011-02-15 | 657-208-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | ANAHEIM | CA |
| 2011-01-31 | 657-212-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | SANTA ANA | CA |
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.