NumberResearchThousands-blocks in 610-603
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 610-603 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
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| — | 610-603-0XXX | 0000–0999 | Reserved | VERIZON PENNSYLVANIA, INC. | 9208 | READING | PA |
| — | 610-603-1XXX | 1000–1999 | Reserved | VERIZON PENNSYLVANIA, INC. | 9208 | READING | PA |
| 2003-04-16 | 610-603-2XXX | 2000–2999 | Assigned | CTSI, INC. - PA | 7513 | READING | PA |
| 2004-08-10 | 610-603-3XXX | 3000–3999 | Assigned | CTSI, INC. - PA | 7513 | READING | PA |
| 2008-10-10 | 610-603-4XXX | 4000–4999 | Assigned | LIMITLESS MOBILE, LLC | 6921 | READING | PA |
| 2004-08-10 | 610-603-5XXX | 5000–5999 | Assigned | CTSI, INC. - PA | 7513 | READING | PA |
| 2006-12-06 | 610-603-6XXX | 6000–6999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - PA | 6392 | READING | PA |
| 2007-01-09 | 610-603-7XXX | 7000–7999 | Assigned | CTSI, INC. - PA | 7513 | READING | PA |
| — | 610-603-8XXX | 8000–8999 | Reserved | VERIZON PENNSYLVANIA, INC. | 9208 | READING | PA |
| — | 610-603-9XXX | 9000–9999 | Reserved | VERIZON PENNSYLVANIA, INC. | 9208 | READING | 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.