Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, all time — NPA 510

PACIFIC BELL 278

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

Recent NPA-NXX prefix assignments
Assigned	NPA-NXX	Thousands-blocks taken (last-4 opening)	Code holder	OCN	Rate center	State
—	510-848	not yet reported which blocks →	PACIFIC BELL	9740	OKLD BKLY	CA
—	510-849	6XXX7XXX · 2 holders which blocks →	PACIFIC BELL	9740	OKLD BKLY	CA
—	510-864	not yet reported which blocks →	PACIFIC BELL	9740	OKLD ALMD	CA
—	510-865	not yet reported which blocks →	PACIFIC BELL	9740	OKLD ALMD	CA
—	510-869	7XXX9XXX · 2 holders which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-873	1XXX3XXX9XXX which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-874	5XXX which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-881	3XXX6XXX which blocks →	PACIFIC BELL	9740	HAYWARD	CA
—	510-883	3XXX4XXX8XXX · 3 holders which blocks →	PACIFIC BELL	9740	OKLD BKLY	CA
—	510-885	not yet reported which blocks →	PACIFIC BELL	9740	HAYWARD	CA
—	510-886	not yet reported which blocks →	PACIFIC BELL	9740	HAYWARD	CA
—	510-887	not yet reported which blocks →	PACIFIC BELL	9740	HAYWARD	CA
—	510-888	not yet reported which blocks →	PACIFIC BELL	9740	HAYWARD	CA
—	510-889	none assigned yet which blocks →	PACIFIC BELL	9740	HAYWARD	CA
—	510-891	1XXX which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-893	not yet reported which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-895	not yet reported which blocks →	PACIFIC BELL	9740	OKLD TRNID	CA
—	510-922	0XXX1XXX8XXX9XXX · 2 holders which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-923	not yet reported which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-936	0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks →	PACIFIC BELL	9740	FRNK MAIN	CA
—	510-964	2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks →	PACIFIC BELL	9740	ELSBR-PINL	CA
—	510-965	2XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks →	PACIFIC BELL	9740	RICHMOND	CA
—	510-970	not yet reported which blocks →	PACIFIC BELL	9740	RICHMOND	CA
—	510-979	2XXX which blocks →	PACIFIC BELL	9740	FRNK OLIVR	CA
—	510-981	9XXX which blocks →	PACIFIC BELL	9740	OKLD BKLY	CA
—	510-985	4XXX9XXX which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-986	4XXX which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA
—	510-987	5XXX6XXX8XXX · 3 holders which blocks →	PACIFIC BELL	9740	OKLD MN-PD	CA

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.