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.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| 2025-03-31 | 563-772 | 0XXX1XXX2XXX3XXX4XXX9XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | CASCADE | IA |
| 2022-08-25 | 563-318 | 0XXX1XXX9XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | TIPTON | IA |
| 2022-04-28 | 563-366 | 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | CRESCO | IA |
| 2022-01-04 | 563-307 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | DUBUQUE | IA |
| 2018-02-12 | 563-396 | 0–9 XXXall 10 · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| 2006-11-16 | 563-537 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | MONONA | IA |
| 2002-01-10 | 563-676 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| 2001-10-30 | 563-528 | 2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| — | 563-213 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | DUBUQUE | IA |
| — | 563-495 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | DUBUQUE | IA |
| — | 563-505 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| — | 563-506 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | MUSCATINE | IA |
| — | 563-516 | 1XXX7XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | ELKADER | IA |
| — | 563-517 | 1XXX2XXX7XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | DECORAH | IA |
| — | 563-518 | 1XXX5XXX6XXX7XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | WEST UNION | IA |
| — | 563-529 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| — | 563-554 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | MUSCATINE | IA |
| — | 563-559 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | CLINTON | IA |
| — | 563-564 | 2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | DUBUQUE | IA |
| — | 563-570 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| — | 563-571 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | MUSCATINE | IA |
| — | 563-579 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| — | 563-593 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | CLINTON | IA |
| — | 563-650 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | DAVENPORT | IA |
| — | 563-889 | not yet reported which blocks → | T-MOBILE USA, INC. | 6529 | TIPTON | IA |
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.