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

CLAYTON prefixes in area code 925

NANPA records 12 assigned NXX blocks to rate center CLAYTON in area code 925, 1.9% of the 640 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. 8 holders hold those blocks, the largest being PACIFIC BELL (3), MCIMETRO ACCESS TRANSMISSION SERVICES LLC (2), T-MOBILE USA, INC. (2). The earliest assignment on record here is 2001-07-17 and the most recent 2002-09-20. 11 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 208, 217, 315, 317 – overlay codes cover the same geography, so a rate center is served by all of them.

12 assigned blocks – 1.9% of 925
8 holders of record
11 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
925-276 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
925-304 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
925-524 AT&T PACIFIC BELL – yes yes
925-567 T-Mobile T-MOBILE USA, INC. 2001-07-17 yes yes
925-672 AT&T PACIFIC BELL – no yes
925-673 AT&T PACIFIC BELL – yes yes
925-690 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
925-693 AT&T TELEPORT COMMUNICATIONS AMERICA, LLC - CA – yes yes
925-844 TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 2001-07-17 yes yes
925-889 MATRIX TELECOM, LLC. S/I/I TNCI - CA – yes yes
925-914 T-Mobile T-MOBILE USA, INC. 2002-09-20 yes yes
925-993 HD CARRIER 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
PACIFIC BELL AT&T 3 25%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC Verizon 2 16.7%
T-MOBILE USA, INC. T-Mobile 2 16.7%
LEVEL 3 COMMUNICATIONS, LLC - CA Lumen 1 8.3%
TELEPORT COMMUNICATIONS AMERICA, LLC - CA AT&T 1 8.3%
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS TPx 1 8.3%
MATRIX TELECOM, LLC. S/I/I TNCI - CA – 1 8.3%
HD CARRIER LLC – 1 8.3%

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 CLAYTON in area code 925?

12 blocks: 276, 304, 524, 567, 672, 673, 690, 693, 844, 889, 914, 993. The table above gives the holder of each.

Which carriers have numbers in CLAYTON?

PACIFIC BELL (3 blocks), MCIMETRO ACCESS TRANSMISSION SERVICES LLC (2 blocks), T-MOBILE USA, INC. (2 blocks), LEVEL 3 COMMUNICATIONS, LLC - CA (1 block), TELEPORT COMMUNICATIONS AMERICA, LLC - CA (1 block), U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is CLAYTON 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 925

All 640 prefixes in 925