NumberResearchThousands-blocks in 410-438
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 410-438 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 410 blocks
Most active assignees, all time — NPA 410
New assignments by month
Sep 2026
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2004-03-05 | 410-438-0XXX | 0000–0999 | Assigned | CORE COMMUNICATIONS, INC.- MD | 2593 | SUDLERSVL | MD |
| 2017-08-31 | 410-438-1XXX | 1000–1999 | Assigned | TELNYX LLC | 073H | SUDLERSVL | MD |
| — | 410-438-2XXX | 2000–2999 | Reserved | VERIZON MARYLAND, INC. | 9212 | SUDLERSVL | MD |
| — | 410-438-3XXX | 3000–3999 | Reserved | VERIZON MARYLAND, INC. | 9212 | SUDLERSVL | MD |
| 2024-01-09 | 410-438-4XXX | 4000–4999 | Assigned | TERRA NOVA TELECOM INC. | 145J | SUDLERSVL | MD |
| — | 410-438-5XXX | 5000–5999 | Available | SUDLERSVL | MD | ||
| 2006-04-10 | 410-438-6XXX | 6000–6999 | Assigned | IDT AMERICA, CORP. - MD | 228C | SUDLERSVL | MD |
| 2016-09-22 | 410-438-7XXX | 7000–7999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - MD | 6119 | SUDLERSVL | MD |
| 2017-03-21 | 410-438-8XXX | 8000–8999 | Assigned | ONVOY, LLC - MD | 876D | SUDLERSVL | MD |
| — | 410-438-9XXX | 9000–9999 | Available | SUDLERSVL | MD |
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.