NumberResearch Membership · Data 09/19/2026

Recent thousands-block assignments

13 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/19/2026

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
2011-12-07 831-574-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 CARMEL CA
2011-11-30 831-975-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SALINAS CA
2011-11-18 831-406-6XXX 6000–6999Assigned U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J WATSONVL CA
2011-11-11 831-684-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 APTOS CA
2011-11-02 831-296-7XXX 7000–7999Assigned METROPCS, INC. 5562 SALINAS CA
2011-10-28 831-293-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 7240 CARMEL CA
2011-10-19 831-293-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 CARMEL CA
2011-09-19 831-319-1XXX 1000–1999Assigned T-MOBILE USA, INC. 6529 WATSONVL CA
2011-09-14 831-205-4XXX 4000–4999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E HOLLISTER CA
2011-09-14 831-217-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C BOULDERCRK CA
2011-09-14 831-290-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C GONZALES CA
2011-09-14 831-508-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C FELTON CA
2011-09-14 831-525-8XXX 8000–8999Assigned AT&T ENTERPRISES, LLC 516C KING CITY CA
2011-09-14 831-532-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C BEN LOMOND CA
2011-09-14 831-593-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C SAN JUAN CA
2011-09-14 831-627-4XXX 4000–4999Assigned AT&T ENTERPRISES, LLC 516C SAN ARDO CA
2011-09-14 831-628-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C TRES PINOS CA
2011-09-01 831-471-8XXX 8000–8999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA CRUZ CA
2011-09-01 831-824-2XXX 2000–2999Assigned PAETEC ITEL, LLC 829J SANTA CRUZ CA
2011-08-31 831-676-0XXX 0000–0999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SALINAS CA
2011-08-30 831-676-4XXX 4000–4999Assigned METROPCS, INC. 5562 SALINAS CA
2011-08-24 831-676-1XXX 1000–1999Assigned METROPCS, INC. 5562 SALINAS CA
2011-08-04 831-287-2XXX 2000–2999Assigned U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J SALINAS CA
2011-08-03 831-264-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E MONTEREY CA
2011-08-03 831-264-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E MONTEREY CA
2011-07-26 831-232-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C CHUALAR CA
2011-07-22 831-824-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E SANTA CRUZ CA
2011-07-21 831-319-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 WATSONVL CA
2011-07-19 831-708-1XXX 1000–1999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E APTOS CA
2011-07-19 831-708-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E APTOS CA
2011-07-13 831-676-2XXX 2000–2999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 SALINAS CA
2011-07-11 831-241-6XXX 6000–6999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L MONTEREY CA
2011-07-11 831-461-4XXX 4000–4999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SANTA CRUZ CA
2011-07-06 831-789-5XXX 5000–5999Assigned METROPCS, INC. 5562 SALINAS CA
2011-07-01 831-264-6XXX 6000–6999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - CA 7145 MONTEREY CA
2011-06-30 831-687-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E APTOS CA
2011-06-30 831-687-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E APTOS CA
2011-06-27 831-205-3XXX 3000–3999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E HOLLISTER CA
2011-06-22 831-297-4XXX 4000–4999Assigned METROPCS, INC. 5562 HOLLISTER CA
2011-06-08 831-237-5XXX 5000–5999Assigned AT&T ENTERPRISES, LLC 516C SOLEDAD CA
2011-06-08 831-406-3XXX 3000–3999Assigned METROPCS, INC. 5562 WATSONVL CA
2011-06-08 831-406-4XXX 4000–4999Assigned METROPCS, INC. 5562 WATSONVL CA
2011-06-08 831-770-9XXX 9000–9999Assigned METROPCS, INC. 5562 SALINAS CA
2011-06-08 831-775-9XXX 9000–9999Assigned METROPCS, INC. 5562 SALINAS CA
2011-05-31 831-204-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E MONTEREY CA
2011-05-31 831-296-4XXX 4000–4999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E SALINAS CA
2011-05-26 831-296-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 SALINAS CA
2011-05-10 831-620-2XXX 2000–2999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 CARMEL CA
2011-04-28 831-296-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E SALINAS CA
2011-04-28 831-296-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - CA 981E SALINAS CA

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.