Area code 357: California
Area code 357 is a US state area code for California, on Pacific Time. It shares its area with 559, so local numbers there can start with any of them. Local calls there take 1 + 10 digits.
Local time in area code 357
America/Los_Angeles
Prefixes in service
No public data
Too new for prefix data
Area code 357 facts
| Location | California, United States |
|---|---|
| Time zone | Pacific Time |
| Overlays | 559 |
| Overlay of | 559 |
| In service since | March 26, 2025 |
| Local calls | 1 + 10 digits |
| Carrier | Not shown. An area code is where a number was issued; numbers port between carriers. Check line type |
How do I dial a 357 number?
NANPA's dialling plan for 357: local calls inside the code take 1 + 10 digits, toll calls 1 + 10 digits. From another area code, dial 1 first. From abroad, use +1. The examples use 555-0147, from a range reserved for fictional numbers.
| Local call inside 357 | 1-357-555-0147 |
|---|---|
| From another US or Canadian area code | 1-357-555-0147 |
| From outside North America | +1 357 555 0147 |
| E.164, for CRMs and SMS tools | +13575550147 |
When did area code 357 start?
Area code 357 went into service on March 26, 2025 as an overlay of 559. Today 357 and 559 cover the same area as an overlay, which is why 10-digit dialling is needed for local calls there.
Tools for 357 numbers
- Area code lookup
Look up any code or a whole list of numbers, or find the codes for a state or city.
- Area code time zone
Local time for a list of numbers, with a callable-now flag.
- NPA-NXX lookup
Rate center and state for one prefix, a level below the area code.
- TCPA calling hours checker
Whether it's inside the federal 8 a.m. to 9 p.m. calling window there now.
Next step
A 357 number tells you where it was issued, not what it is now.
Mobiles, landlines and VoIP lines share area codes, and numbers move between carriers. A live line-type and carrier lookup on every number in your list says which is which, and that decides which calling and texting rules apply. It's in the Email + Phone plan.
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Area code 357 questions
- What state is area code 357?
- Area code 357 is in California, United States.
- What time zone is area code 357 in?
- Pacific Time.
- What area codes overlay 357?
- 559. An overlay adds a new code to the same area instead of splitting it, so neighbours can have different area codes and local calls need 10 digits.
- When did area code 357 start?
- Area code 357 went into service on March 26, 2025 as an overlay of 559.
- Is a 357 number a cell phone or a landline?
- The area code can't tell you. In the US and Canada mobiles, landlines and VoIP lines share area codes and prefixes, and numbers move between carriers and line types. Only a live line-type lookup answers it for one number.
Other area codes in California
209213279310323341350369408415424442510530559562619626628650657661669707714738747760805818820831837840858909916925949951
Sources
Location, overlays, in-service date and dialling plan: NANPA NPA database, file dated 10/16/2026. Prefixes and rate centers: NANPA central office code assignments, 10/17/2026. Time zones mapped to the IANA time zone database. By the SimpleVerifier Team; how we build these pages.