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 313
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2016-04-18 | 313-326-6XXX | 6000–6999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN5 | MI |
| 2016-03-23 | 313-509-2XXX | 2000–2999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN2 | MI |
| 2015-02-24 | 313-855-6XXX | 6000–6999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN4 | MI |
| 2015-01-12 | 313-789-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN6 | MI |
| 2014-12-02 | 313-818-0XXX | 0000–0999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN1 | MI |
| 2014-10-17 | 313-365-7XXX | 7000–7999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN3 | MI |
| 2014-07-02 | 313-466-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN2 | MI |
| 2014-04-16 | 313-307-8XXX | 8000–8999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN4 | MI |
| 2013-05-22 | 313-472-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN5 | MI |
| 2013-01-09 | 313-922-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN2 | MI |
| 2012-12-19 | 313-340-2XXX | 2000–2999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN4 | MI |
| 2012-01-13 | 313-724-6XXX | 6000–6999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN6 | MI |
| 2011-06-17 | 313-436-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN6 | MI |
| 2009-04-10 | 313-722-4XXX | 4000–4999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN6 | MI |
| 2009-01-15 | 313-694-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN5 | MI |
| 2008-12-23 | 313-473-8XXX | 8000–8999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN2 | MI |
| 2008-11-07 | 313-270-7XXX | 7000–7999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN4 | MI |
| 2006-06-08 | 313-736-3XXX | 3000–3999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN4 | MI |
| 2006-06-08 | 313-926-6XXX | 6000–6999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN2 | MI |
| 2006-02-02 | 313-731-7XXX | 7000–7999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN3 | MI |
| 2006-01-19 | 313-740-7XXX | 7000–7999 | Assigned | AT&T ENTERPRISES, LLC | 516C | DETROITZN5 | MI |
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.