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

ST CLAIR prefixes in area code 636

NANPA records 6 assigned NXX blocks to rate center ST CLAIR in area code 636, 1.4% of the 435 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. 5 holders hold those blocks, the largest being SOUTHWESTERN BELL (2), ONVOY, LLC - MO (1), LEVEL 3 COMMUNICATIONS, LLC - MO (1). The earliest assignment on record here is 2003-01-10 and the most recent 2024-06-12. 5 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots. The same rate center name also appears in area codes 272, 507, 570, 810 – overlay codes cover the same geography, so a rate center is served by all of them.

6 assigned blocks – 1.4% of 636
5 holders of record
5 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
636-276 Onvoy ONVOY, LLC - MO 2024-06-12 yes yes
636-322 AT&T SOUTHWESTERN BELL 2006-01-10 yes yes
636-364 Lumen LEVEL 3 COMMUNICATIONS, LLC - MO 2003-01-10 yes yes
636-629 AT&T SOUTHWESTERN BELL – no yes
636-758 FRACTEL, LLC 2019-10-25 yes yes
636-888 Peerless PEERLESS NETWORK OF MISSOURI, LLC - MO 2014-01-21 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
SOUTHWESTERN BELL AT&T 2 33.3%
ONVOY, LLC - MO Onvoy 1 16.7%
LEVEL 3 COMMUNICATIONS, LLC - MO Lumen 1 16.7%
FRACTEL, LLC – 1 16.7%
PEERLESS NETWORK OF MISSOURI, LLC - MO Peerless 1 16.7%

Same rate center in other codes

Overlay codes cover the same geography, so one rate center is served by all of them.

Frequently asked

Which prefixes belong to ST CLAIR in area code 636?

6 blocks: 276, 322, 364, 629, 758, 888. The table above gives the holder of each.

Which carriers have numbers in ST CLAIR?

SOUTHWESTERN BELL (2 blocks), ONVOY, LLC - MO (1 block), LEVEL 3 COMMUNICATIONS, LLC - MO (1 block), FRACTEL, LLC (1 block), PEERLESS NETWORK OF MISSOURI, LLC - MO (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is ST CLAIR 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 636

All 435 prefixes in 636