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

TWIN LAKE prefixes in area code 231

NANPA records 3 assigned NXX blocks to rate center TWIN LAKE 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. 2 holders hold those blocks, the largest being ONVOY, LLCV - MI (2), FRONTIER NORTH, INC. - MI (1). The earliest assignment on record here is 2015-06-16 and the most recent 2021-07-02. 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
2 holders of record
3 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
231-376 Onvoy ONVOY, LLCV - MI 2021-07-02 yes yes
231-828 Frontier FRONTIER NORTH, INC. - MI – yes yes
231-888 Onvoy ONVOY, LLCV - MI 2015-06-16 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
ONVOY, LLCV - MI Onvoy 2 66.7%
FRONTIER NORTH, INC. - MI Frontier 1 33.3%

Frequently asked

Which prefixes belong to TWIN LAKE in area code 231?

3 blocks: 376, 828, 888. The table above gives the holder of each.

Which carriers have numbers in TWIN LAKE?

ONVOY, LLCV - MI (2 blocks), FRONTIER NORTH, INC. - MI (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is TWIN LAKE 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