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 231
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
Mar 2026
Feb 2026
Jan 2026
Dec 2025
Nov 2025
Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2021-12-07 | 231-296-1XXX | 1000–1999 | Assigned | IP HORIZON LLC | 515J | FREMONT | MI |
| 2021-12-07 | 231-381-1XXX | 1000–1999 | Assigned | IP HORIZON LLC | 515J | WHITECLOUD | MI |
| 2021-12-07 | 231-387-8XXX | 8000–8999 | Assigned | IP HORIZON LLC | 515J | PETOSKEY | MI |
| 2021-12-07 | 231-390-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | BIG RAPIDS | MI |
| 2021-12-07 | 231-396-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | CADILLAC | MI |
| 2021-12-07 | 231-397-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | MANISTEE | MI |
| 2021-12-07 | 231-465-9XXX | 9000–9999 | Assigned | IP HORIZON LLC | 515J | REED CITY | MI |
| 2021-12-07 | 231-600-5XXX | 5000–5999 | Assigned | IP HORIZON LLC | 515J | TRAVERSECY | MI |
| 2021-12-07 | 231-624-2XXX | 2000–2999 | Assigned | IP HORIZON LLC | 515J | KALKASKA | MI |
| 2021-12-07 | 231-974-1XXX | 1000–1999 | Assigned | IP HORIZON LLC | 515J | GRANT | 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.