NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026
The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.
Most active assignees, all time — NPA 581
New assignments by month
Sep 2026
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Oct 2025
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| 2024-05-16 | 581-436 | not yet reported which blocks → | Iristel Inc. | 154E | Maria | — |
| 2024-03-04 | 581-432 | not yet reported which blocks → | Iristel Inc. | 154E | Sainte-Marie-de-Beauce | — |
| 2023-10-19 | 581-942 | not yet reported which blocks → | Iristel Inc. | 154E | Riviere-du-Loup | — |
| 2023-05-05 | 581-403 | not yet reported which blocks → | Iristel Inc. | 154E | Quebec | — |
| 2023-01-31 | 581-402 | not yet reported which blocks → | Iristel Inc. | 346J | Rimouski | — |
| 2023-01-25 | 581-439 | not yet reported which blocks → | Iristel Inc. | 346J | Sainte-Anne-des-Monts | — |
| 2023-01-25 | 581-468 | not yet reported which blocks → | Iristel Inc. | 346J | Sainte-Anne-des-Monts | — |
| 2023-01-25 | 581-469 | not yet reported which blocks → | Iristel Inc. | 346J | Sainte-Anne-des-Monts | — |
| 2022-02-03 | 581-690 | not yet reported which blocks → | Iristel Inc. | 154E | Chicoutimi | — |
| 2022-02-01 | 581-465 | not yet reported which blocks → | Iristel Inc. | 154E | Matane | — |
| 2022-01-27 | 581-685 | not yet reported which blocks → | Iristel Inc. | 154E | Sept-Iles | — |
| 2022-01-25 | 581-410 | not yet reported which blocks → | Iristel Inc. | 154E | Sainte-Marie-de-Beauce | — |
| 2022-01-24 | 581-474 | not yet reported which blocks → | Iristel Inc. | 154E | Donnacona | — |
| 2022-01-19 | 581-893 | not yet reported which blocks → | Iristel Inc. | 154E | Chandler | — |
| 2021-05-05 | 581-895 | not yet reported which blocks → | Iristel Inc. | 154E | Riviere-du-Loup | — |
| 2020-09-22 | 581-202 | not yet reported which blocks → | Iristel Inc. | 154E | Alma | — |
| 2020-09-14 | 581-892 | not yet reported which blocks → | Iristel Inc. | 154E | Quebec | — |
| 2020-01-30 | 581-441 | not yet reported which blocks → | Iristel Inc. | 154E | Bonaventure | — |
| 2020-01-30 | 581-499 | not yet reported which blocks → | Iristel Inc. | 154E | Carleton | — |
| 2020-01-30 | 581-870 | not yet reported which blocks → | Iristel Inc. | 154E | Thetford Mines | — |
| 2020-01-30 | 581-900 | not yet reported which blocks → | Iristel Inc. | 154E | Baie-Trinite | — |
| 2020-01-17 | 581-890 | not yet reported which blocks → | Iristel Inc. | 154E | Quebec | — |
| 2020-01-17 | 581-891 | not yet reported which blocks → | Iristel Inc. | 154E | Quebec | — |
| 2019-10-29 | 581-470 | not yet reported which blocks → | Iristel Inc. | 346J | Bonaventure | — |
| 2019-10-29 | 581-489 | not yet reported which blocks → | Iristel Inc. | 346J | Sainte-Anne-des-Monts | — |
| 2019-10-29 | 581-780 | not yet reported which blocks → | Iristel Inc. | 346J | Havre-Saint-Pierre | — |
| 2019-10-29 | 581-871 | not yet reported which blocks → | Iristel Inc. | 346J | Natashquan | — |
| 2019-10-28 | 581-471 | not yet reported which blocks → | Iristel Inc. | 346J | Chandler | — |
| 2019-10-24 | 581-408 | not yet reported which blocks → | Iristel Inc. | 346J | Rimouski | — |
| 2019-10-24 | 581-409 | not yet reported which blocks → | Iristel Inc. | 346J | Baie-Comeau | — |
| 2019-09-16 | 581-506 | not yet reported which blocks → | Iristel Inc. | 154E | Rimouski | — |
| 2019-07-30 | 581-872 | not yet reported which blocks → | Iristel Inc. | 154E | Quebec | — |
| 2019-07-30 | 581-873 | not yet reported which blocks → | Iristel Inc. | 154E | Quebec | — |
| 2019-07-30 | 581-874 | not yet reported which blocks → | Iristel Inc. | 154E | Quebec | — |
| 2019-07-04 | 581-875 | not yet reported which blocks → | Iristel Inc. | 154E | Chicoutimi | — |
| 2019-07-04 | 581-876 | not yet reported which blocks → | Iristel Inc. | 154E | Chibougamau | — |
| 2019-05-03 | 581-203 | not yet reported which blocks → | Iristel Inc. | 154E | Alma | — |
| 2018-07-17 | 581-796 | not yet reported which blocks → | Iristel Inc. | 154E | Natashquan | — |
| 2018-07-17 | 581-809 | not yet reported which blocks → | Iristel Inc. | 154E | Port-Cartier | — |
| 2018-07-13 | 581-480 | not yet reported which blocks → | Iristel Inc. | 154E | Sainte-Anne-des-Monts | — |
| 2018-07-13 | 581-517 | not yet reported which blocks → | Iristel Inc. | 154E | Baie-Trinite | — |
| 2018-07-13 | 581-518 | not yet reported which blocks → | Iristel Inc. | 154E | Amqui | — |
| 2018-07-13 | 581-519 | not yet reported which blocks → | Iristel Inc. | 154E | Mont-Louis | — |
| 2018-07-13 | 581-797 | not yet reported which blocks → | Iristel Inc. | 154E | Havre-Saint-Pierre | — |
| 2018-07-13 | 581-798 | not yet reported which blocks → | Iristel Inc. | 154E | Mont-Joli | — |
| 2018-07-13 | 581-799 | not yet reported which blocks → | Iristel Inc. | 154E | Saint-Fabien | — |
| 2018-07-12 | 581-515 | not yet reported which blocks → | Iristel Inc. | 154E | Port-Daniel | — |
| 2018-07-12 | 581-516 | not yet reported which blocks → | Iristel Inc. | 154E | Forestville | — |
| 2018-07-12 | 581-877 | not yet reported which blocks → | Iristel Inc. | 154E | Grande-Vallee | — |
| 2018-07-12 | 581-878 | not yet reported which blocks → | Iristel Inc. | 154E | Perce | — |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.