NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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 628
FRACTEL, LLC 33
ONVOY, LLC - CA 32
T-MOBILE USA, INC. 28
TELEPORT COMMUNICATIONS AMERICA, LLC - CA 17
BANDWIDTH.COM CLEC, LLC - CA 13
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
2018-12-05 628-264 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SNFC CNTRL CA
2018-05-15 628-263 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 7240 SNFC CNTRL CA
2018-05-01 628-280 0–9 XXXall 10 · 7 holders which blocks → SONIC TELECOM, LLC - CA 433E SNFC MT-EV CA
2018-03-27 628-273 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SNFC CNTRL CA
2018-03-27 628-274 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SNFC CNTRL CA
2018-03-27 628-275 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SNFC CNTRL CA
2018-03-06 628-363 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SNFC JUNPR CA
2018-02-23 628-262 0–9 XXXall 10 · 5 holders which blocks → EXIANT COMMUNICATIONS LLC 114J BELVEDERE CA
2018-02-15 628-561 0–9 XXXall 10 · 5 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F STNSN-BLNS CA
2018-01-29 628-260 0–9 XXXall 10 · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 SNFC CNTRL CA
2018-01-18 628-230 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SNFC CNTRL CA
2018-01-04 628-652 0–9 XXXwhole prefix which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 SNFC CNTRL CA
2017-11-09 628-502 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SNFC CNTRL CA
2017-10-26 628-259 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 IGNACIO CA
2017-10-19 628-258 0–9 XXXall 10 · 7 holders which blocks → T-MOBILE USA, INC. 6529 NICASIO CA
2017-10-04 628-250 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SNFC JUNPR CA
2017-09-20 628-240 0–9 XXXall 10 · 8 holders which blocks → METROPCS, INC. 5562 SAN RAFAEL CA
2017-07-27 628-219 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 SNFC MT-EV CA
2017-06-16 628-218 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 7240 SNFC CNTRL CA
2017-03-24 628-867 0–9 XXXall 10 · 5 holders which blocks → COMMIO, LLC 939H SNFC CNTRL CA
2017-02-10 628-255 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SNFC CNTRL CA
2017-02-03 628-249 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SNFC CNTRL CA
2017-02-03 628-895 0–9 XXXall 10 · 9 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SNFC CNTRL CA
2016-12-15 628-209 0–9 XXXall 10 · 6 holders which blocks → TELNYX LLC 073H NOVATO CA
2016-12-01 628-213 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 SNFC CNTRL CA
2016-10-28 628-257 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → RACE TELECOMMUNICATIONS, INC. - CA 973E MILLVALLEY CA
2016-10-17 628-251 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F SNFC CNTRL CA
2016-10-17 628-256 0–9 XXXall 10 · 6 holders which blocks → SONIC TELECOM, LLC - CA 433E SNFC MT-EV CA
2016-09-20 628-212 0–9 XXXall 10 · 5 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E CORTEMADRA CA
2016-09-20 628-214 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F NOVATO CA
2016-09-20 628-215 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E MILLVALLEY CA
2016-09-20 628-216 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E POINTREYES CA
2016-09-19 628-210 0–9 XXXall 10 · 5 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F INVERNESS CA
2016-08-23 628-254 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E SAUSALITO CA
2016-08-22 628-217 0–9 XXXall 10 · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 SNFC CNTRL CA
2016-08-22 628-244 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F BELVEDERE CA
2016-08-09 628-208 0–9 XXXall 10 · 5 holders which blocks → VONAGE AMERICA LLC 197D SNFC CNTRL CA
2016-07-29 628-207 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E SNFC MT-EV CA
2016-07-27 628-205 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SNFC CNTRL CA
2016-07-25 628-253 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E SAN RAFAEL CA
2016-07-22 628-239 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E SNFC JUNPR CA
2016-07-22 628-246 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - CA 981E SNFC CNTRL CA
2016-07-19 628-247 0–9 XXXwhole prefix which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 SNFC CNTRL CA
2016-07-19 628-248 0–9 XXXwhole prefix which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 SNFC MT-EV CA
2016-07-14 628-245 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - CA 649C MILLVALLEY CA
2016-07-01 628-204 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 NICASIO CA
2016-07-01 628-241 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 SNFC JUNPR CA
2016-07-01 628-252 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 CORTEMADRA CA
2016-06-27 628-203 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - CA 649C STNSN-BLNS CA
2016-04-29 628-229 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - CA 649C POINTREYES CA

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.