NumberResearchThousands-blocks in 717-591
This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/20/2026
The ten 1,000-number thousand-blocks inside prefix 717-591 and who was initially assigned each. Under pooling these blocks often belong to different carriers — the single prefix-level “assignee” is usually just the pool / code holder, not who holds the numbers. ← all 717 blocks
Most active assignees, all time — NPA 717
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 |
|---|---|---|---|---|---|---|---|
| — | 717-591-0XXX | 0000–0999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-1XXX | 1000–1999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-2XXX | 2000–2999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-3XXX | 3000–3999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-4XXX | 4000–4999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-5XXX | 5000–5999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| 2015-01-13 | 717-591-6XXX | 6000–6999 | Assigned | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-7XXX | 7000–7999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-8XXX | 8000–8999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
| — | 717-591-9XXX | 9000–9999 | Reserved | CTSI, INC. - PA | 7513 | MECHANCSBG | PA |
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.