Recent prefix assignments

2 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, last 30 days — NPA 557

NEW CINGULAR WIRELESS PCS, LLC - IL 2

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
2023-11-15	557-215	0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks →	CALLWORKS CORPORATION	475J	ST LOUIS	MO
2023-11-15	557-217	0–9 XXXall 10 · 3 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	SAPPINGTON	MO
2023-11-13	557-214	0–9 XXXwhole prefix which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	ST LOUIS	MO
2023-09-29	557-212	0–9 XXXall 10 · 5 holders which blocks →	T-MOBILE USA, INC.	6529	MEHLVILLE	MO
2023-09-29	557-213	0–9 XXXall 10 · 3 holders which blocks →	NEW CINGULAR WIRELESS PCS, LLC - IL	6534	ST LOUIS	MO
2023-09-21	557-210	0–9 XXXall 10 · 5 holders which blocks →	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO	5814	LADUE	MO
2023-09-07	557-208	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MO	093F	LADUE	MO
2023-08-16	557-507	0–9 XXXwhole prefix which blocks →	ONVOY SPECTRUM, LLC	624H	ST LOUIS	MO
2023-06-15	557-207	0–9 XXXall 10 · 4 holders which blocks →	FIVE9, INC.	598J	OAKVILLE	MO
2023-06-01	557-205	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-06-01	557-206	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-06-01	557-216	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-05-22	557-204	0–9 XXXall 10 · 6 holders which blocks →	FIVE9, INC.	598J	ST LOUIS	MO
2023-05-19	557-203	0–9 XXXall 10 · 4 holders which blocks →	T-MOBILE USA, INC.	6529	MEHLVILLE	MO
2023-05-15	557-557	0–9 XXXall 10 · 2 holders which blocks →	ONVOY, LLC - MO	093F	ST LOUIS	MO
2023-05-04	557-222	0–9 XXXall 10 · 5 holders which blocks →	LEAP TELECOM, LLC	616J	ST LOUIS	MO
2023-04-14	557-201	0–9 XXXall 10 · 3 holders which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	KIRKWOOD	MO
2023-03-27	557-202	0–9 XXXall 10 · 5 holders which blocks →	COMCAST IP PHONE, LLC	318J	ST LOUIS	MO
2023-01-25	557-273	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-01-25	557-362	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-01-25	557-454	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-01-25	557-653	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-01-25	557-747	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-01-25	557-953	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2023-01-25	557-996	0–9 XXXwhole prefix which blocks →	TELEPORT COMMUNICATIONS AMERICA, LLC - MO	7218	ST LOUIS	MO
2022-09-16	557-888	0–9 XXXall 10 · 2 holders which blocks →	TERRA NOVA TELECOM INC.	145J	KIRKWOOD	MO
2022-09-16	557-999	0–9 XXXall 10 · 6 holders which blocks →	WIRETAP TELECOM, LLC.	733J	SAPPINGTON	MO
2022-08-24	557-777	0–9 XXXall 10 · 5 holders which blocks →	TERRA NOVA TELECOM INC.	145J	CREVECOEUR	MO
2022-08-12	557-500	0–9 XXXall 10 · 3 holders which blocks →	ONVOY SPECTRUM, LLC	624H	ST LOUIS	MO
2022-08-08	557-200	0–9 XXXall 10 · 3 holders which blocks →	ONVOY, LLC - MO	093F	LADUE	MO
2022-08-08	557-467	0–9 XXXwhole prefix which blocks →	ONVOY, LLC - MO	093F	ST LOUIS	MO
—	557-211	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-311	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-411	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-511	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-555	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	DIR ASST	MO
—	557-611	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-700	not yet reported which blocks →				MO
—	557-711	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-811	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-911	not yet reported which blocks →	MULTIPLE OCN LISTING	MULT	XXXXXXXXXX	MO
—	557-950	not yet reported which blocks →				MO
—	557-958	not yet reported which blocks →				MO
—	557-959	not yet reported which blocks →				MO
—	557-976	not yet reported which blocks →				MO

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.