NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

0 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, all time — NPA 331
STRATUS NETWORKS 18
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
2020-11-13 331-310-5XXX 5000–5999Assigned STRATUS NETWORKS 495J BIG ROCK IL
2020-09-14 331-264-9XXX 9000–9999Assigned STRATUS NETWORKS 495J HINSDALE IL
2020-09-11 331-265-0XXX 0000–0999Assigned STRATUS NETWORKS 495J GENEVA IL
2020-09-05 331-348-0XXX 0000–0999Assigned STRATUS NETWORKS 495J ELBURN IL
2020-09-05 331-867-0XXX 0000–0999Assigned STRATUS NETWORKS 495J YORKVILLE IL
2020-09-05 331-946-0XXX 0000–0999Assigned STRATUS NETWORKS 495J GLEN ELLYN IL
2020-08-31 331-232-8XXX 8000–8999Assigned STRATUS NETWORKS 495J W CHICAGO IL
2020-08-31 331-252-8XXX 8000–8999Assigned STRATUS NETWORKS 495J WARRENVL IL
2020-08-31 331-259-0XXX 0000–0999Assigned STRATUS NETWORKS 495J SUGARGROVE IL
2020-08-31 331-266-0XXX 0000–0999Assigned STRATUS NETWORKS 495J ST CHARLES IL
2020-08-31 331-600-1XXX 1000–1999Assigned STRATUS NETWORKS 495J WHEATON IL
2020-08-30 331-249-9XXX 9000–9999Assigned STRATUS NETWORKS 495J NAPERVILLE IL
2020-08-30 331-261-0XXX 0000–0999Assigned STRATUS NETWORKS 495J LEMONT IL
2020-08-30 331-263-9XXX 9000–9999Assigned STRATUS NETWORKS 495J ITASCA IL
2020-08-30 331-400-8XXX 8000–8999Assigned STRATUS NETWORKS 495J OSWEGO IL
2020-08-30 331-704-9XXX 9000–9999Assigned STRATUS NETWORKS 495J KANEVILLE IL
2020-08-30 331-808-7XXX 7000–7999Assigned STRATUS NETWORKS 495J PLANO IL
2020-08-26 331-666-9XXX 9000–9999Assigned STRATUS NETWORKS 495J AURORA IL

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.