NumberResearchRecent thousands-block assignments
1 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, last 30 days — NPA 312
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2004-03-05 | 312-525-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2004-02-17 | 312-239-2XXX | 2000–2999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | CHICGOZN01 | IL |
| 2004-02-09 | 312-476-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2004-02-09 | 312-521-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2004-01-28 | 312-731-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2004-01-28 | 312-731-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-12-19 | 312-546-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-11-14 | 312-348-8XXX | 8000–8999 | Assigned | ONVOY, LLC | 224C | CHICGOZN01 | IL |
| 2003-10-22 | 312-451-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-10-10 | 312-521-7XXX | 7000–7999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | CHICGOZN01 | IL |
| 2003-09-05 | 312-479-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-08-22 | 312-479-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-08-12 | 312-451-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-08-12 | 312-451-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-08-12 | 312-479-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-08-12 | 312-479-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-08-12 | 312-479-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-07-30 | 312-451-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-07-15 | 312-451-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-07-15 | 312-451-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-07-15 | 312-451-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-07-15 | 312-451-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-07-15 | 312-451-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-0XXX | 0000–0999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-1XXX | 1000–1999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-2XXX | 2000–2999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-3XXX | 3000–3999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-4XXX | 4000–4999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-5XXX | 5000–5999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-6XXX | 6000–6999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-7XXX | 7000–7999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-8XXX | 8000–8999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-06-24 | 312-325-9XXX | 9000–9999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-05-13 | 312-685-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | CHICGOZN01 | IL |
| 2003-05-06 | 312-395-1XXX | 1000–1999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2003-01-23 | 312-252-7XXX | 7000–7999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2002-12-23 | 312-395-2XXX | 2000–2999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2002-12-23 | 312-395-3XXX | 3000–3999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2002-12-23 | 312-395-4XXX | 4000–4999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2002-12-19 | 312-395-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
| 2002-12-19 | 312-395-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
| 2002-12-19 | 312-395-8XXX | 8000–8999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
| 2002-12-10 | 312-237-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
| 2002-10-25 | 312-521-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
| 2002-10-21 | 312-521-1XXX | 1000–1999 | Assigned | PEERLESS NETWORK OF ILLINOIS, LLC - IL | 063E | CHICGOZN01 | IL |
| 2002-10-02 | 312-395-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
| 2002-10-01 | 312-252-6XXX | 6000–6999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2002-09-27 | 312-604-6XXX | 6000–6999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
| 2002-09-17 | 312-768-2XXX | 2000–2999 | Assigned | ILLINOIS BELL TEL CO | 9329 | CHICGOZN01 | IL |
| 2002-08-26 | 312-994-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | CHICGOZN01 | IL |
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.