NumberResearchThousands-blocks in 878-355
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 878-355 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 878 blocks
Most active assignees, all time — NPA 878
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| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2017-08-15 | 878-355-0XXX | 0000–0999 | Assigned | IDT AMERICA, CORP. - PA | 213C | UNIONTOWN | PA |
| 2017-11-02 | 878-355-1XXX | 1000–1999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - PA | 6392 | UNIONTOWN | PA |
| 2018-06-14 | 878-355-2XXX | 2000–2999 | Assigned | CORE COMMUNICATIONS, INC. - PA | 3806 | UNIONTOWN | PA |
| 2018-06-14 | 878-355-3XXX | 3000–3999 | Assigned | CORE COMMUNICATIONS, INC. - PA | 3806 | UNIONTOWN | PA |
| 2018-06-14 | 878-355-4XXX | 4000–4999 | Assigned | CORE COMMUNICATIONS, INC. - PA | 3806 | UNIONTOWN | PA |
| 2017-08-11 | 878-355-5XXX | 5000–5999 | Assigned | METROPCS, INC. | 5562 | UNIONTOWN | PA |
| 2019-02-13 | 878-355-6XXX | 6000–6999 | Assigned | COMCAST IP PHONE, LLC | 318J | UNIONTOWN | PA |
| 2017-06-02 | 878-355-7XXX | 7000–7999 | Assigned | AERIAL COMMUNICATIONS, INC. | 6701 | UNIONTOWN | PA |
| 2017-06-02 | 878-355-8XXX | 8000–8999 | Assigned | AERIAL COMMUNICATIONS, INC. | 6701 | UNIONTOWN | PA |
| 2017-06-02 | 878-355-9XXX | 9000–9999 | Assigned | AERIAL COMMUNICATIONS, INC. | 6701 | UNIONTOWN | 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.