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 |
|---|---|---|---|---|---|---|
| 2016-07-28 | 717-663 | 0–9 XXXall 10 · 4 holders which blocks → | CTSI, INC. - PA | 7513 | LANCASTER | PA |
| 2012-09-26 | 717-947 | 0–9 XXXall 10 · 7 holders which blocks → | CTSI, INC. - PA | 7513 | LANCASTER | PA |
| 2009-09-21 | 717-461 | 0–9 XXXall 10 · 4 holders which blocks → | CTSI, INC. - PA | 7513 | HARISBGZN1 | PA |
| 2007-09-26 | 717-614 | 0–9 XXXall 10 · 6 holders which blocks → | CTSI, INC. - PA | 7513 | HARISBGZN1 | PA |
| 2002-02-11 | 717-370 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | CTSI, INC. - PA | 7513 | HARISBGZN2 | PA |
| 2002-01-03 | 717-376 | 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | CTSI, INC. - PA | 7513 | LEBANON | PA |
| 2002-01-03 | 717-835 | 3XXX8XXX9XXX · 2 holders which blocks → | CTSI, INC. - PA | 7513 | HERSHEY | PA |
| — | 717-358 | 8XXX9XXX · 2 holders which blocks → | CTSI, INC. - PA | 7513 | LANCASTER | PA |
| — | 717-509 | not yet reported which blocks → | CTSI, INC. - PA | 7513 | LANCASTER | PA |
| — | 717-591 | 6XXX which blocks → | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-718 | 5XXX6XXX7XXX8XXX · 2 holders which blocks → | CTSI, INC. - PA | 7513 | YORK | PA |
| — | 717-901 | not yet reported which blocks → | CTSI, INC. - PA | 7513 | HARISBGZN1 | PA |
| — | 717-902 | 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | CTSI, INC. - PA | 7513 | MIDDLETOWN | PA |
| — | 717-909 | not yet reported which blocks → | CTSI, INC. - PA | 7513 | HARISBGZN1 | PA |
| — | 717-920 | not yet reported which blocks → | CTSI, INC. - PA | 7513 | HARISBGZN1 | PA |
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.