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

KING CITY prefixes in area code 831

NANPA records 7 assigned NXX blocks to rate center KING CITY in area code 831, 1.7% 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. 6 holders hold those blocks, the largest being PACIFIC BELL (2), IP HORIZON LLC (1), BANDWIDTH.COM CLEC, LLC - CA (1). The earliest assignment on record here is 2020-07-24 and the most recent 2023-12-06. 6 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 660 – overlay codes cover the same geography, so a rate center is served by all of them.

7 assigned blocks – 1.7% of 831
6 holders of record
6 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
831-263 IP HORIZON LLC – yes yes
831-385 AT&T PACIFIC BELL – no yes
831-386 AT&T PACIFIC BELL – yes yes
831-387 Bandwidth BANDWIDTH.COM CLEC, LLC - CA – yes yes
831-525 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
831-830 Onvoy ONVOY, LLC - CA 2020-07-24 yes yes
831-931 Charter ONVOY SPECTRUM, LLC 2023-12-06 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 28.6%
IP HORIZON LLC – 1 14.3%
BANDWIDTH.COM CLEC, LLC - CA Bandwidth 1 14.3%
LEVEL 3 COMMUNICATIONS, LLC - CA Lumen 1 14.3%
ONVOY, LLC - CA Onvoy 1 14.3%
ONVOY SPECTRUM, LLC Charter 1 14.3%

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 KING CITY in area code 831?

7 blocks: 263, 385, 386, 387, 525, 830, 931. The table above gives the holder of each.

Which carriers have numbers in KING CITY?

PACIFIC BELL (2 blocks), IP HORIZON LLC (1 block), BANDWIDTH.COM CLEC, LLC - CA (1 block), LEVEL 3 COMMUNICATIONS, LLC - CA (1 block), ONVOY, LLC - CA (1 block), ONVOY SPECTRUM, 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 KING CITY 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