NumberResearch Membership · Data 09/20/2026

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 857
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 67
OMNIPOINT MIAMI E LICENSE, LLC 61
ONVOY, LLC - MA 42
METROPCS, INC. 25
PAETEC ITEL, LLC 19
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
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2018-11-06 857-799 0–9 XXXall 10 · 5 holders which blocks → HD CARRIER LLC 321J CAMBRIDGE MA
2018-09-20 857-349 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E WINTHROP MA
2018-07-13 857-347 0–9 XXXall 10 · 5 holders which blocks → ADVANCED TELECOM SOLUTIONS, LLC 181J BOSTON MA
2018-05-23 857-346 0–9 XXXall 10 · 4 holders which blocks → TELENGY LLC 148J BOSTON MA
2018-04-09 857-344 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 QUINCY MA
2018-02-13 857-343 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2018-01-25 857-338 0–9 XXXall 10 · 4 holders which blocks → TC SYSTEMS, INC. 7135 BOSTON MA
2018-01-15 857-332 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-12-29 857-329 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-12-06 857-324 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-12-06 857-326 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-10-27 857-322 0–9 XXXall 10 · 5 holders which blocks → COMCAST IP PHONE, LLC 318J EASTBOSTON MA
2017-10-17 857-306 0–9 XXXall 10 · 2 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J BOSTON MA
2017-10-17 857-315 0–9 XXXall 10 · 5 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J BOSTON MA
2017-09-22 857-298 0–9 XXXall 10 · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H CAMBRIDGE MA
2017-08-22 857-297 0–9 XXXall 10 · 5 holders which blocks → COMCAST IP PHONE, LLC 318J NEWTON MA
2017-08-16 857-296 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-08-08 857-292 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-08-08 857-295 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-08-07 857-291 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-05-22 857-443 0–9 XXXall 10 · 4 holders which blocks → COMMIO, LLC 939H BOSTON MA
2017-05-16 857-290 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 NEWTON MA
2017-05-01 857-289 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - MA 892D BOSTON MA
2017-04-28 857-286 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-04-27 857-283 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-02-02 857-895 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2017-02-01 857-378 0–9 XXXall 10 · 5 holders which blocks → VERIZON NEW ENGLAND INC. 9102 BOSTON MA
2017-01-31 857-287 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 BOSTON MA
2017-01-23 857-393 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2016-10-25 857-424 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ROXBURY MA
2016-09-21 857-409 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2016-09-21 857-505 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 BOSTON MA
2016-09-21 857-507 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2016-09-12 857-773 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → METROPCS, INC. 5562 JAMAICA PL MA
2016-09-06 857-425 0–9 XXXall 10 · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BRIGHTON MA
2016-08-12 857-410 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E CHARLESTN MA
2016-08-08 857-419 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 MILTON MA
2016-08-04 857-386 0–9 XXXall 10 · 6 holders which blocks → VERIZON NEW ENGLAND INC. 9102 CHELSEA MA
2016-07-27 857-772 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2016-07-22 857-763 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT MIAMI E LICENSE, LLC 6889 BOSTON MA
2016-07-18 857-762 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 BOSTON MA
2016-06-21 857-760 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MA 990E WATERTOWN MA
2016-06-01 857-385 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 DORCHESTER MA
2016-05-09 857-971 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - MA 892D CHARLESTN MA
2016-03-01 857-336 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - MA 892D WINTHROP MA
2016-02-26 857-280 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - MA 892D BRIGHTON MA
2016-02-11 857-577 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - MA 892D CHARLESTN MA
2016-02-10 857-477 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - MA 892D JAMAICA PL MA
2016-01-29 857-274 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 BOSTON MA
2016-01-29 857-279 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MA 6387 NEWTON MA

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.