NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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 231
TELNET WORLDWIDE, INC. 43
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
2012-05-11 231-291 0–9 XXXwhole prefix which blocks → TELNET WORLDWIDE, INC. 817J MUSKEGON MI
2004-03-25 231-209 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J SUTTONSBAY MI
2004-03-24 231-205 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J BRUTUS MI
2004-03-24 231-207 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J HONOR MI
2004-03-24 231-208 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J BOYNEFALLS MI
2004-03-24 231-217 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J BEAR LAKE MI
2004-03-24 231-219 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MERRITT MI
2004-03-24 231-226 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J GLEN LAKE MI
2004-03-24 231-230 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J ELMIRA MI
2004-03-24 231-232 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MOORESTOWN MI
2004-03-24 231-235 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J LEVERING MI
2004-03-24 231-236 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J LAKE CITY MI
2004-03-24 231-240 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J LAKE ANN MI
2004-03-24 231-243 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J ALANSON MI
2002-04-22 231-682 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J ALDEN MI
2001-08-31 231-637 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J NORTHPORT MI
2001-08-31 231-764 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J FIFE LAKE MI
2001-08-27 231-647 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J CORAL MI
2001-08-27 231-822 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J BEULAH MI
2001-08-27 231-902 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J HART MI
2001-07-11 231-695 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J HOWARDCITY MI
— 231-305 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J BIG RAPIDS MI
— 231-306 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J CADILLAC MI
— 231-308 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J CHARLEVOIX MI
— 231-309 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MANISTEE MI
— 231-312 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J FRANKFORT MI
— 231-314 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J KALKASKA MI
— 231-316 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J LUDINGTON MI
— 231-319 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MACKINAWCY MI
— 231-332 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MUSKEGON MI
— 231-344 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J PETOSKEY MI
— 231-346 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J TRAVERSECY MI
— 231-351 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J SCOTTVILLE MI
— 231-353 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MCBAIN MI
— 231-355 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J FREMONT MI
— 231-356 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MANCELONA MI
— 231-358 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J CENTRAL LK MI
— 231-361 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MORLEY MI
— 231-363 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J CHEBOYGAN MI
— 231-365 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J WOLVERINE MI
— 231-368 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J BALDWIN MI
— 231-372 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J EVART MI
— 231-395 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J GRANT MI

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.