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
2020-07-07 831-348-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 WATSONVL CA
2020-06-30 831-356-8XXX 8000–8999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 SALINAS CA
2020-06-29 831-243-2XXX 2000–2999Assigned CSC WIRELESS, LLC 425J SALINAS CA
2020-06-17 831-257-5XXX 5000–5999Assigned ONVOY SPECTRUM, LLC 624H APTOS CA
2020-06-17 831-257-6XXX 6000–6999Assigned ONVOY SPECTRUM, LLC 624H APTOS CA
2020-06-17 831-257-7XXX 7000–7999Assigned ONVOY SPECTRUM, LLC 624H APTOS CA
2020-06-15 831-348-7XXX 7000–7999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 WATSONVL CA
2020-06-11 831-529-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 SANTA CRUZ CA
2020-06-09 831-208-8XXX 8000–8999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 6006 SALINAS CA
2020-05-22 831-220-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 MONTEREY CA
2020-05-22 831-348-0XXX 0000–0999Assigned CHARTER IP ENABLED SERVICES, LLC 792K WATSONVL CA
2020-05-13 831-231-7XXX 7000–7999Assigned ONVOY, LLC - CA 649C GREENFIELD CA
2020-05-13 831-231-8XXX 8000–8999Assigned ONVOY, LLC - CA 649C GREENFIELD CA
2020-05-13 831-630-4XXX 4000–4999Assigned ONVOY, LLC - CA 649C HOLLISTER CA
2020-05-13 831-630-8XXX 8000–8999Assigned ONVOY, LLC - CA 649C HOLLISTER CA
2020-05-11 831-292-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 SOLEDAD CA
2020-05-06 831-297-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 HOLLISTER CA
2020-05-06 831-348-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 WATSONVL CA
2020-05-06 831-356-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 SALINAS CA
2020-05-06 831-356-6XXX 6000–6999Assigned T-MOBILE USA, INC. 6529 SALINAS CA
2020-04-21 831-576-0XXX 0000–0999Assigned AIRESPRING, INC. 996H SANTA CRUZ CA
2020-03-30 831-529-3XXX 3000–3999Assigned FRACTEL, LLC 965H SANTA CRUZ CA
2020-03-30 831-529-9XXX 9000–9999Assigned FRACTEL, LLC 965H SANTA CRUZ CA
2020-03-18 831-220-6XXX 6000–6999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 MONTEREY CA
2020-03-18 831-220-7XXX 7000–7999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 MONTEREY CA
2020-03-16 831-760-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 MONTEREY CA
2020-03-16 831-760-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 MONTEREY CA
2020-03-10 831-996-9XXX 9000–9999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F TRES PINOS CA
2020-03-04 831-439-2XXX 2000–2999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L SANTA CRUZ CA
2020-03-04 831-889-2XXX 2000–2999Assigned T-MOBILE USA, INC. 6529 SANTA CRUZ CA
2020-03-03 831-889-4XXX 4000–4999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F SANTA CRUZ CA
2020-02-10 831-705-1XXX 1000–1999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F CHUALAR CA
2020-02-04 831-231-4XXX 4000–4999Assigned ONVOY, LLC - CA 649C GREENFIELD CA
2020-02-04 831-231-5XXX 5000–5999Assigned ONVOY, LLC - CA 649C GREENFIELD CA
2020-02-04 831-387-9XXX 9000–9999Assigned ONVOY, LLC - CA 649C KING CITY CA
2020-01-31 831-877-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 CARMEL CA
2020-01-31 831-877-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 CARMEL CA
2020-01-31 831-877-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 CARMEL CA
2020-01-08 831-208-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 SALINAS CA
2020-01-08 831-877-9XXX 9000–9999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 CARMEL CA
2019-12-18 831-249-0XXX 0000–0999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F BIG SUR CA
2019-12-18 831-337-6XXX 6000–6999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F BOULDERCRK CA
2019-12-18 831-532-0XXX 0000–0999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F BEN LOMOND CA
2019-12-18 831-889-1XXX 1000–1999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F SANTA CRUZ CA
2019-12-02 831-356-7XXX 7000–7999Assigned FRACTEL, LLC 965H SALINAS CA
2019-12-02 831-356-9XXX 9000–9999Assigned FRACTEL, LLC 965H SALINAS CA
2019-11-26 831-855-9XXX 9000–9999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F MONTEREY CA
2019-11-22 831-902-4XXX 4000–4999Assigned PEERLESS NETWORK OF CALIFORNIA, LLC - CA 373F HOLLISTER CA
2019-09-23 831-760-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 MONTEREY CA
2019-09-23 831-760-8XXX 8000–8999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 MONTEREY 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.