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

WASCO prefixes in area code 661

NANPA records 8 assigned NXX blocks to rate center WASCO in area code 661, 1.2% of the 674 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 IP HORIZON LLC (1), LEVEL 3 COMMUNICATIONS, LLC - CA (1), TWILIO INTERNATIONAL, INC. (1). The earliest assignment on record here is 2019-10-04 and the most recent 2022-06-29. 7 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 541 – overlay codes cover the same geography, so a rate center is served by all of them.

8 assigned blocks – 1.2% of 661
8 holders of record
7 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
661-240 IP HORIZON LLC – yes yes
661-438 Lumen LEVEL 3 COMMUNICATIONS, LLC - CA – yes yes
661-560 Twilio TWILIO INTERNATIONAL, INC. – yes yes
661-590 TPx U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 2022-06-29 yes yes
661-758 AT&T PACIFIC BELL – no yes
661-759 T-Mobile METROPCS, INC. – yes yes
661-772 Lumen LEVEL 3 TELECOM OF CALIFORNIA, LP - CA – yes yes
661-884 Onvoy ONVOY, LLC - CA 2019-10-04 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
IP HORIZON LLC – 1 12.5%
LEVEL 3 COMMUNICATIONS, LLC - CA Lumen 1 12.5%
TWILIO INTERNATIONAL, INC. Twilio 1 12.5%
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS TPx 1 12.5%
PACIFIC BELL AT&T 1 12.5%
METROPCS, INC. T-Mobile 1 12.5%
LEVEL 3 TELECOM OF CALIFORNIA, LP - CA Lumen 1 12.5%
ONVOY, LLC - CA Onvoy 1 12.5%

Frequently asked

Which prefixes belong to WASCO in area code 661?

8 blocks: 240, 438, 560, 590, 758, 759, 772, 884. The table above gives the holder of each.

Which carriers have numbers in WASCO?

IP HORIZON LLC (1 block), LEVEL 3 COMMUNICATIONS, LLC - CA (1 block), TWILIO INTERNATIONAL, INC. (1 block), U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS (1 block), PACIFIC BELL (1 block), METROPCS, INC. (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is WASCO 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 661

All 674 prefixes in 661