NumberResearchThousands-blocks in 610-553
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 610-553 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 610 blocks
Most active assignees, all time — NPA 610
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 |
|---|---|---|---|---|---|---|---|
| 2016-08-24 | 610-553-0XXX | 0000–0999 | Assigned | NUSO, LLC | 551G | PHPHSBZN17 | PA |
| 2003-01-14 | 610-553-1XXX | 1000–1999 | Assigned | SERVICE ELECTRIC TELEPHONE COMPANY, LLC | 8320 | PHPHSBZN17 | PA |
| 2023-02-07 | 610-553-2XXX | 2000–2999 | Assigned | ONVOY, LLC - PA | 547E | PHPHSBZN17 | PA |
| 2005-02-24 | 610-553-3XXX | 3000–3999 | Assigned | PAETEC ITEL, LLC | 829J | PHPHSBZN17 | PA |
| 2014-03-11 | 610-553-4XXX | 4000–4999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | PHPHSBZN17 | PA |
| 2008-06-05 | 610-553-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - PA | 7434 | PHPHSBZN17 | PA |
| 2020-02-04 | 610-553-6XXX | 6000–6999 | Assigned | PEERLESS NETWORK OF PENNSYLVANIA, LLC - PA | 967E | PHPHSBZN17 | PA |
| 2014-06-10 | 610-553-7XXX | 7000–7999 | Assigned | COMCAST IP PHONE, LLC | 318J | PHPHSBZN17 | PA |
| 2016-08-24 | 610-553-8XXX | 8000–8999 | Assigned | NUSO, LLC | 551G | PHPHSBZN17 | PA |
| — | 610-553-9XXX | 9000–9999 | Reserved | TELEPORT COMMUNICATIONS AMERICA, LLC - PA | 7309 | PHPHSBZN17 | 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.