NumberResearchRecent thousands-block assignments
0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/20/2026
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 510
New assignments by month
Sep 2026
Aug 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2016-05-11 | 510-696-1XXX | 1000–1999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD FRTVL | CA |
| 2015-07-01 | 510-679-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD BKLY | CA |
| 2015-06-15 | 510-850-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD TRNID | CA |
| 2015-05-13 | 510-640-0XXX | 0000–0999 | Assigned | AT&T ENTERPRISES, LLC | 516C | ELSBR-PINL | CA |
| 2015-04-09 | 510-674-9XXX | 9000–9999 | Assigned | AT&T ENTERPRISES, LLC | 516C | HAYWARD | CA |
| 2014-10-02 | 510-952-0XXX | 0000–0999 | Assigned | AT&T ENTERPRISES, LLC | 516C | FRNK GRNLF | CA |
| 2014-05-06 | 510-823-2XXX | 2000–2999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD MN-PD | CA |
| 2014-04-01 | 510-878-1XXX | 1000–1999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD TRNID | CA |
| 2014-03-31 | 510-876-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | HAYWARD | CA |
| 2013-10-09 | 510-680-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | RICHMOND | CA |
| 2013-09-17 | 510-320-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | FRNK MAIN | CA |
| 2013-08-21 | 510-328-1XXX | 1000–1999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD FRTVL | CA |
| 2012-10-29 | 510-398-8XXX | 8000–8999 | Assigned | AT&T ENTERPRISES, LLC | 516C | HAYWARD | CA |
| 2011-09-20 | 510-250-9XXX | 9000–9999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD MN-PD | CA |
| 2011-05-04 | 510-455-9XXX | 9000–9999 | Assigned | AT&T ENTERPRISES, LLC | 516C | CROCKETT | CA |
| 2010-06-23 | 510-567-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD TRNID | CA |
| 2010-06-09 | 510-460-9XXX | 9000–9999 | Assigned | AT&T ENTERPRISES, LLC | 516C | HAYWARD | CA |
| 2007-08-09 | 510-565-1XXX | 1000–1999 | Assigned | AT&T ENTERPRISES, LLC | 516C | FRNK MAIN | CA |
| 2006-10-19 | 510-283-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | ELSBR-PINL | CA |
| 2006-10-19 | 510-327-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | HRCUL-RODE | CA |
| 2006-06-09 | 510-274-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | HAYWARD | CA |
| 2006-05-15 | 510-529-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD BKLY | CA |
| 2006-05-15 | 510-817-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD MN-PD | CA |
| 2006-04-11 | 510-374-6XXX | 6000–6999 | Assigned | AT&T ENTERPRISES, LLC | 516C | RICHMOND | CA |
| 2006-04-11 | 510-431-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | FRNK GRNLF | CA |
| 2006-03-10 | 510-263-8XXX | 8000–8999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD ALMD | CA |
| 2006-03-10 | 510-270-8XXX | 8000–8999 | Assigned | AT&T ENTERPRISES, LLC | 516C | FRNK OLIVR | CA |
| 2006-03-10 | 510-479-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | OKLD FRTVL | 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.