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 206
QWEST CORPORATION 243
T-MOBILE USA, INC. 95
ONVOY, LLC - WA 72
NEW CINGULAR WIRELESS PCS, LLC 58
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 57
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
2014-06-11 206-556 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 SEATTLE WA
2014-04-04 206-597 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SEATTLE WA
2014-03-28 206-294 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2014-01-02 206-474 0–9 XXXall 10 · 4 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7173 SEATTLE WA
2013-11-01 206-435 0–9 XXXall 10 · 2 holders which blocks → LEVEL 3 TELECOM OF WASHINGTON, LLC - WA 7455 SEATTLE WA
2013-10-31 206-939 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2013-10-23 206-946 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - WA 483E SEATTLE WA
2013-10-22 206-348 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 SEATTLE WA
2013-08-01 206-981 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2013-07-30 206-582 0–9 XXXall 10 · 6 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7173 SEATTLE WA
2013-07-18 206-305 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 SEATTLE WA
2013-05-15 206-258 0–9 XXXall 10 · 4 holders which blocks → COMCAST IP PHONE, LLC 318J SEATTLE WA
2013-05-09 206-602 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2012-12-20 206-489 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2012-11-02 206-858 0–9 XXXall 10 · 5 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7173 SEATTLE WA
2012-10-12 206-735 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WA 5812 SEATTLE WA
2012-10-09 206-557 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 SEATTLE WA
2012-10-04 206-549 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2012-03-19 206-477 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9638 SEATTLE WA
2012-03-12 206-209 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - WA 483E SEATTLE WA
2012-02-08 206-454 0–9 XXXall 10 · 5 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7173 SEATTLE WA
2012-02-08 206-596 0–9 XXXall 10 · 4 holders which blocks → INTRADO COMMUNICATIONS, LLC 841C SEATTLE WA
2012-01-25 206-486 0–9 XXXwhole prefix which blocks → PEERLESS NETWORK OF WASHINGTON, LLC - WA 159F SEATTLE WA
2011-12-16 206-639 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - WA 483E SEATTLE WA
2011-12-12 206-643 0–9 XXXall 10 · 2 holders which blocks → NUSO, LLC 551G SEATTLE WA
2011-11-09 206-641 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SEATTLE WA
2011-10-17 206-747 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 SEATTLE WA
2011-10-04 206-538 0–9 XXXall 10 · 5 holders which blocks → PAETEC ITEL, LLC 829J SEATTLE WA
2011-08-09 206-535 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2011-06-08 206-512 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2010-12-29 206-743 0–9 XXXall 10 · 5 holders which blocks → PEERLESS NETWORK OF WASHINGTON, LLC - WA 159F SEATTLE WA
2010-10-05 206-430 0–9 XXXall 10 · 6 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J SEATTLE WA
2009-10-01 206-395 0–9 XXXall 10 · 3 holders which blocks → BANDWIDTH.COM CLEC, LLC - WA 006F SEATTLE WA
2009-08-03 206-317 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7173 BAINBDG IS WA
2009-06-23 206-707 0–9 XXXall 10 · 3 holders which blocks → IP HORIZON LLC 515J SEATTLE WA
2008-11-06 206-787 0–9 XXXall 10 · 4 holders which blocks → QWEST CORPORATION 9638 SEATTLE WA
2008-10-27 206-659 0–9 XXXall 10 · 3 holders which blocks → COMCAST IP PHONE, LLC 318J SEATTLE WA
2008-10-01 206-432 0–9 XXXall 10 · 4 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7173 SEATTLE WA
2008-08-01 206-414 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - WA 483E SEATTLE WA
2008-06-18 206-552 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - WA 006F SEATTLE WA
2008-05-22 206-402 0–9 XXXall 10 · 3 holders which blocks → ELTOPIA COMMUNICATIONS, LLC - WA 663D SEATTLE WA
2008-05-15 206-452 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2008-05-15 206-588 0–9 XXXall 10 · 6 holders which blocks → COMCAST IP PHONE, LLC 318J SEATTLE WA
2008-05-13 206-458 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2007-08-27 206-518 0–9 XXXall 10 · 4 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7173 SEATTLE WA
2007-08-15 206-453 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2007-08-15 206-455 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - WA 6121 SEATTLE WA
2007-05-07 206-307 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - WA 483E SEATTLE WA
2007-04-26 206-446 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA
2007-03-29 206-631 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 SEATTLE WA

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.