NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026
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 |
|---|---|---|---|---|---|---|
| 2016-12-09 | 605-560 | 0XXX1XXX · 2 holders which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | BROOKINGSR | SD |
| 2010-08-04 | 605-304 | 1XXX which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | WHITE | SD |
| 2010-08-04 | 605-414 | 1XXX4XXX · 2 holders which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | CASTLEWOOD | SD |
| 2010-08-04 | 605-686 | 1XXX6XXX8XXX · 2 holders which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | ESTELLINE | SD |
| 2010-08-04 | 605-710 | 0XXX1XXX · 2 holders which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | LAKENORDEN | SD |
| 2010-08-04 | 605-792 | 1XXX which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | HAYTI | SD |
| 2010-08-04 | 605-922 | 1XXX2XXX · 2 holders which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | ELKTON | SD |
| 2010-06-23 | 605-632 | 1XXX which blocks → | MCC TELEPHONY OF THE MID-WEST, LLC - SD | 920F | LK PRESTON | SD |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.