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

RNCHOSANFE prefixes in area code 858

NANPA records 14 assigned NXX blocks to rate center RNCHOSANFE in area code 858, 2.5% of the 564 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. 12 holders hold those blocks, the largest being PACIFIC BELL (2), LEVEL 3 COMMUNICATIONS, LLC - CA (2), MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA (1). The earliest assignment on record here is 2002-08-30 and the most recent 2004-11-05. 12 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 code 619 – overlay codes cover the same geography, so a rate center is served by all of them.

14 assigned blocks – 2.5% of 858
12 holders of record
12 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
858-227 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA – yes yes
858-310 Twilio TWILIO INTERNATIONAL, INC. – yes yes
858-367 IP HORIZON LLC – yes yes
858-381 AT&T TELEPORT COMMUNICATIONS AMERICA, LLC - CA – yes yes
858-400 TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS – yes yes
858-504 T-Mobile T-MOBILE USA, INC. 2002-08-30 yes yes
858-756 AT&T PACIFIC BELL – no yes
858-759 AT&T PACIFIC BELL – no yes
858-771 AT&T AT&T ENTERPRISES, LLC 2004-11-05 yes yes
858-779 Lumen LEVEL 3 TELECOM OF CALIFORNIA, LP - CA – yes yes
858-832 Comcast COMCAST PHONE OF CALIFORNIA, LLC – yes yes
858-914 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
858-923 MATRIX TELECOM, LLC. S/I/I TNCI - CA – yes yes
858-951 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – 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 2 14.3%
LEVEL 3 COMMUNICATIONS, LLC - CA Lumen 2 14.3%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA Verizon 1 7.1%
TWILIO INTERNATIONAL, INC. Twilio 1 7.1%
IP HORIZON LLC – 1 7.1%
TELEPORT COMMUNICATIONS AMERICA, LLC - CA AT&T 1 7.1%
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS TPx 1 7.1%
T-MOBILE USA, INC. T-Mobile 1 7.1%
AT&T ENTERPRISES, LLC AT&T 1 7.1%
LEVEL 3 TELECOM OF CALIFORNIA, LP - CA Lumen 1 7.1%
COMCAST PHONE OF CALIFORNIA, LLC Comcast 1 7.1%
MATRIX TELECOM, LLC. S/I/I TNCI - CA – 1 7.1%

Frequently asked

Which prefixes belong to RNCHOSANFE in area code 858?

14 blocks: 227, 310, 367, 381, 400, 504, 756, 759, 771, 779, 832, 914 and 2 more, all listed in the table above.

Which carriers have numbers in RNCHOSANFE?

PACIFIC BELL (2 blocks), LEVEL 3 COMMUNICATIONS, LLC - CA (2 blocks), MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA (1 block), TWILIO INTERNATIONAL, INC. (1 block), IP HORIZON LLC (1 block), TELEPORT COMMUNICATIONS AMERICA, LLC - CA (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is RNCHOSANFE 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 858

All 564 prefixes in 858