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

TRES PINOS prefixes in area code 831

NANPA records 6 assigned NXX blocks to rate center TRES PINOS in area code 831, 1.5% of the 406 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. 4 holders hold those blocks, the largest being LEVEL 3 COMMUNICATIONS, LLC - CA (3), PACIFIC BELL (1), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA (1). The earliest assignment on record here is 2006-05-11 and the most recent 2006-05-11. 6 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

6 assigned blocks – 1.5% of 831
4 holders of record
6 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
831-299 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
831-350 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA 2006-05-11 yes yes
831-628 AT&T PACIFIC BELL – yes yes
831-821 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA – yes yes
831-921 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
831-996 IP HORIZON LLC – 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
LEVEL 3 COMMUNICATIONS, LLC - CA Lumen 3 50%
PACIFIC BELL AT&T 1 16.7%
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA Verizon 1 16.7%
IP HORIZON LLC – 1 16.7%

Frequently asked

Which prefixes belong to TRES PINOS in area code 831?

6 blocks: 299, 350, 628, 821, 921, 996. The table above gives the holder of each.

Which carriers have numbers in TRES PINOS?

LEVEL 3 COMMUNICATIONS, LLC - CA (3 blocks), PACIFIC BELL (1 block), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA (1 block), IP HORIZON LLC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is TRES PINOS 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 831

All 406 prefixes in 831