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 331
New assignments by month
Sep 2026
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2017-09-01 | 331-219-7XXX | 7000–7999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | AURORA | IL |
| 2016-06-01 | 331-903-1XXX | 1000–1999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | DOWNERSGRV | IL |
| 2015-06-18 | 331-806-1XXX | 1000–1999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | WHEATON | IL |
| 2015-01-20 | 331-701-4XXX | 4000–4999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | NAPERVILLE | IL |
| 2014-02-26 | 331-318-5XXX | 5000–5999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | LEMONT | IL |
| 2010-03-10 | 331-642-6XXX | 6000–6999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ELMHURST | IL |
| 2010-03-04 | 331-457-6XXX | 6000–6999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | NAPERVILLE | IL |
| 2009-12-30 | 331-551-5XXX | 5000–5999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | LOMBARD | IL |
| 2007-12-06 | 331-456-0XXX | 0000–0999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-1XXX | 1000–1999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-2XXX | 2000–2999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-3XXX | 3000–3999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-4XXX | 4000–4999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-5XXX | 5000–5999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-6XXX | 6000–6999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-7XXX | 7000–7999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-8XXX | 8000–8999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | IL |
| 2007-12-06 | 331-456-9XXX | 9000–9999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | ROSELLE | 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.