NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

IRONS prefixes in area code 231

NANPA records 3 assigned NXX blocks to rate center IRONS in area code 231, 0.5% of the 572 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 3 holders hold those blocks, the largest being MICHIGAN BELL TEL CO (1), CHARTER IP ENABLED SERVICES, LLC (1), NEW CINGULAR WIRELESS PCS, LLC - IL (1). The earliest assignment on record here is 2002-08-30 and the most recent 2021-05-13. 3 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

3 assigned blocks – 0.5% of 231
3 holders of record
3 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
231-266 AT&T MICHIGAN BELL TEL CO – yes yes
231-298 Charter CHARTER IP ENABLED SERVICES, LLC 2021-05-13 yes yes
231-729 AT&T NEW CINGULAR WIRELESS PCS, LLC - IL 2002-08-30 yes yes

The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.

Who holds the blocks

HolderBrandBlocksShare here
MICHIGAN BELL TEL CO AT&T 1 33.3%
CHARTER IP ENABLED SERVICES, LLC Charter 1 33.3%
NEW CINGULAR WIRELESS PCS, LLC - IL AT&T 1 33.3%

Frequently asked

Which prefixes belong to IRONS in area code 231?

3 blocks: 266, 298, 729. The table above gives the holder of each.

Which carriers have numbers in IRONS?

MICHIGAN BELL TEL CO (1 block), CHARTER IP ENABLED SERVICES, LLC (1 block), NEW CINGULAR WIRELESS PCS, LLC - IL (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is IRONS a city?

It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.

Other rate centers in 231

All 572 prefixes in 231