NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

13 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/20/2026

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

Most carrier growth happens here, not at the prefix level: under number pooling, carriers receive individual 1,000-number blocks (e.g. 626-470-0XXX) within already-assigned prefixes. Assignments are initial assignments — the current serving carrier of individual numbers may differ due to portability.

Most active assignees, last 30 days — NPA 831
ONVOY, LLC - CA 10
EXIANT COMMUNICATIONS LLC 2
BANDWIDTH.COM CLEC, LLC - CA 1
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 thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2012-09-21 831-275-1XXX 1000–1999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E MONTEREY CA
2012-09-21 831-275-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E MONTEREY CA
2012-09-10 831-756-6XXX 6000–6999Assigned METROPCS, INC. 5562 SALINAS CA
2012-09-10 831-756-8XXX 8000–8999Assigned METROPCS, INC. 5562 SALINAS CA
2012-09-10 831-756-9XXX 9000–9999Assigned METROPCS, INC. 5562 SALINAS CA
2012-09-10 831-783-8XXX 8000–8999Assigned METROPCS, INC. 5562 SALINAS CA
2012-08-21 831-435-6XXX 6000–6999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SANTA CRUZ CA
2012-08-21 831-465-4XXX 4000–4999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SANTA CRUZ CA
2012-08-21 831-821-2XXX 2000–2999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 TRES PINOS CA
2012-08-20 831-760-9XXX 9000–9999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 MONTEREY CA
2012-08-03 831-316-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SANTA CRUZ CA
2012-08-03 831-319-4XXX 4000–4999Assigned CHARTER IP ENABLED SERVICES, LLC 792K WATSONVL CA
2012-08-01 831-316-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SANTA CRUZ CA
2012-07-17 831-428-4XXX 4000–4999Assigned METROPCS, INC. 5562 SANTA CRUZ CA
2012-07-17 831-428-6XXX 6000–6999Assigned METROPCS, INC. 5562 SANTA CRUZ CA
2012-07-16 831-204-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E MONTEREY CA
2012-07-16 831-316-4XXX 4000–4999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E SANTA CRUZ CA
2012-07-13 831-288-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 WATSONVL CA
2012-07-13 831-319-2XXX 2000–2999Assigned T-MOBILE USA, INC. 6529 WATSONVL CA
2012-06-28 831-222-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 FELTON CA
2012-06-28 831-316-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SANTA CRUZ CA
2012-06-12 831-717-7XXX 7000–7999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 MONTEREY CA
2012-05-10 831-319-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 WATSONVL CA
2012-05-09 831-710-9XXX 9000–9999Assigned METROPCS, INC. 5562 SALINAS CA
2012-05-08 831-222-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E FELTON CA
2012-04-25 831-710-3XXX 3000–3999Assigned METROPCS, INC. 5562 SALINAS CA
2012-04-25 831-710-5XXX 5000–5999Assigned METROPCS, INC. 5562 SALINAS CA
2012-04-25 831-710-6XXX 6000–6999Assigned METROPCS, INC. 5562 SALINAS CA
2012-04-25 831-710-8XXX 8000–8999Assigned METROPCS, INC. 5562 SALINAS CA
2012-04-23 831-316-3XXX 3000–3999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E SANTA CRUZ CA
2012-04-09 831-869-7XXX 7000–7999Assigned METROPCS, INC. 5562 MONTEREY CA
2012-04-04 831-800-8XXX 8000–8999Assigned ONVOY, LLC - CA 649C SALINAS CA
2012-04-03 831-800-0XXX 0000–0999Assigned ONVOY, LLC - CA 649C SALINAS CA
2012-03-21 831-205-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E HOLLISTER CA
2012-03-20 831-246-7XXX 7000–7999Assigned ONVOY, LLC - CA 649C BEN LOMOND CA
2012-03-20 831-704-8XXX 8000–8999Assigned ONVOY, LLC - CA 649C FELTON CA
2012-03-14 831-461-5XXX 5000–5999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SANTA CRUZ CA
2012-02-21 831-789-4XXX 4000–4999Assigned METROPCS, INC. 5562 SALINAS CA
2012-02-21 831-789-7XXX 7000–7999Assigned METROPCS, INC. 5562 SALINAS CA
2012-02-15 831-237-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SOLEDAD CA
2012-02-15 831-525-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 KING CITY CA
2012-02-10 831-824-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SANTA CRUZ CA
2012-02-02 831-705-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 7240 CHUALAR CA
2011-12-16 831-265-9XXX 9000–9999Assigned METROPCS, INC. 5562 HOLLISTER CA
2011-12-15 831-665-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 HOLLISTER CA
2011-12-15 831-741-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 CASTROVL CA
2011-12-15 831-856-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 GREENFIELD CA
2011-12-15 831-920-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 MONTEREY CA
2011-12-14 831-324-6XXX 6000–6999Assigned U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J MONTEREY CA
2011-12-13 831-705-2XXX 2000–2999Assigned U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J CHUALAR CA

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.