---
title: "Area code 661: California, United States"
url: "https://lookvalid.com/area-code/661.md"
canonical_url: "https://lookvalid.com/area-code/661"
last_updated: "2026-10-23"
type: "reference"
summary: "Area code 661 serves California, United States. Number formats, numbering rules, a live phone validator and the other codes in California."
---

# Area code 661: California, United States

Area code 661 serves California, United States. Number formats, numbering rules, a live phone validator and the other codes in California.

NANPA lists 668 central office codes (prefixes) in use in area code 661, held by 50 holders across 32 rate centers.
Pacific Bell holds the most prefixes, 144 (22%). 79% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
The FCC unwanted-call data has 3,100 complaints on file for 2,281 numbers in 661, most often filed as "Unwanted Calls". These are consumer reports, not findings.

## Facts

- In service since: 1999-02-13
- Time zone: Pacific (P)
- Prefixes in use: 668
- Pooled prefixes: 525 (79%)
- Rate centers: 32
- Companies holding prefixes: 50
- Assignment dates on file: 2001-02-07 to 2026-03-30 (258 prefixes)
- ZIP codes in its places: 26

## Rate centers

| Rate center | Prefixes | Share |
| --- | --- | --- |
| BKFD MAIN | 149 | 22% |
| PLDL PLDL | 95 | 14% |
| SNCA NHCS | 66 | 10% |
| LANCASTER | 55 | 8% |
| BKFD SOUTH | 49 | 7% |
| BKFD NORTH | 29 | 4% |
| SNCA SGCC | 29 | 4% |
| DELANO | 23 | 3% |
| 24 other rate centers | 173 | 26% |

## Carriers

| Holder | Prefixes | Share |
| --- | --- | --- |
| Pacific Bell | 144 | 22% |
| New Cingular Wireless PCS | 75 | 11% |
| T-Mobile USA | 55 | 8% |
| Verizon Wireless | 49 | 7% |
| Onvoy | 47 | 7% |
| Level 3 Communications | 35 | 5% |
| 44 other carriers | 263 | 39% |

A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company.

## History

- 1957-01-01: Area code 805, named as the parent of 661 in the NANPA report, was in service.
- 1999-02-13: Area code 661 went into service.

## Nearest area codes

The area codes closest to 661, measured between the centers of the ZIP code places they serve, are 747 (about 69 miles), 805 (about 69 miles), 818 (about 69 miles), 820 (about 70 miles) and 626 (about 83 miles).

## ZIP codes

26 ZIP codes fall in places that have a rate center in this area code. The places with the most are Lancaster, CA (6 ZIP codes), Delano, CA (2 ZIP codes) and Edwards, CA (2 ZIP codes). A ZIP code and an area code are unrelated systems, so a ZIP code can sit in more than one area code and an area code spans many ZIP codes.

## Complaints on file

3,100 complaints for 2,281 numbers. Numbers whose latest complaint falls in each year:

- 2023: 113
- 2024: 134
- 2025: 92

## Questions

### Where is area code 661?

NANPA assigns area code 661 to California, United States.

### In which state does area code 661 sit?

California. 661 is one of 41 area codes the NANPA table assigns to the state.

### Which places does area code 661 cover?

The places with the most ZIP codes among the rate centers in 661 are Lancaster, CA, Delano, CA and Edwards, CA. The rate center list on this page shows all of them.

### Who owns area code 661?

NANPA assigns area codes. Within 661, Pacific Bell holds the most prefixes, 144 prefixes or 22%.

### Which time zone does 661 use?

The NANPA NPA report lists the time zone for 661 as Pacific (P).

### What year did 661 enter service?

The NANPA NPA report gives an in-service date of 1999-02-13, so 661 has been in use since 1999.

### Does area code 661 have an overlay?

The NANPA NPA report lists no other area code in an overlay with 661.

### Which area codes are nearest to 661?

The area codes closest to 661, measured between the centers of the ZIP code places they serve, are 747 (about 69 miles), 805 (about 69 miles), 818 (about 69 miles), 820 (about 70 miles) and 626 (about 83 miles).

### How many prefixes does area code 661 have?

NANPA's report dated 2026-10-17 lists 668 prefixes in service in 661, spread over 32 rate centers and 50 holders.

### Are there complaints about 661 numbers?

The FCC data on file has 3,100 complaints for 2,281 numbers in 661. They are unverified consumer reports. A number with no complaints on file is not proven safe.

Sources: NANPA central office code report dated 2026-10-17; NANPA NPA report dated 2026-10-18; FCC unwanted-call complaints, data fetched 2026-10-17; ZIP code places from GeoNames (CC BY 4.0).