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US area code · California

Area code 840

Where the 840 area code is, its overlay and how to dial a +1 840 number from anywhere.

CoversCaliforniaTime zonePacific (PT)TypeOverlay
Quick answer

The 840 area code is in California, United States (Pacific (PT)). To call from abroad: +1 840 555-0123. It is an overlay, so all 10 digits are dialled.

StateCalifornia
Time zonePacific (PT)
TypeOverlay
10-digit dialingRequired
In service since13-Jun-2019

The 840 area code is a geographic North American Numbering Plan (NANP) code covering California. It has been in service since 13-Jun-2019 and sits in the Pacific (PT) time zone.

Overlay 840 shares its region

Several area codes cover the same geographic area, so two neighbours can have different codes. Because of the overlay, you must dial all 10 digits (area code + number) even for local calls.

840909

How to dial a 840 number

From abroad+1 840 555-0123
Within the US / Canada1 840 555-0123
Locally (same area)840 555-0123

Other California area codes

209213279310323341350357369408415424442510530559

Frequently asked questions

Where is the 840 area code?

The 840 area code is in California, United States (Pacific (PT)).

Is 840 an overlay area code?

Yes. 840 overlays the same region as 909, so callers dial all 10 digits.

Do I have to dial 10 digits for 840?

Yes — dial the area code plus the seven-digit number.

How do I call a 840 number from another country?

Dial your exit code (or +), then 1, then 840, then the number: +1 840 555-0123.

Source: NANPA numbering plan. An area code covers a region, not a precise address — a 840 number does not pinpoint a street or ZIP code.

Missed a call from +1 840?

In the 30 days to September 24, 2026, 210 unwanted calls showing a 840 number were reported to the US Federal Trade Commission, 78% of them recorded messages or robocalls. That puts 840 at #330 of 670 area codes reported.

Reducing your debt (credit cards, mortgage, student loans)108
Other66
Calls pretending to be government, businesses, or family and friends24
Dropped call or no message3
Before you call back
  • If you do not know anyone in California, do not call back: a genuine caller will leave a message or send a text.
  • Scammers fake the number shown on caller ID, so a 840 number can hide a caller anywhere in the world.
  • Never give a code received by text or a bank detail to an unknown caller. In the US, calls can be reported at reportfraud.ftc.gov.

Who issues +1 840 numbers

Phone companies hold blocks of numbers in each area code. The main holders in 840:

T-Mobile USA, Inc. 32Fractel, LLC 26Onvoy, LLC 22New Cingular Wireless PCS, LLC 17Cellco Partnership Dba Verizon Wireless 12Multiple Ocn Listing 9

About 43.6% of the 140 prefixes in use belong to mobile carriers: a 840 number is often a cell phone, and it may have moved to another carrier since.

Sources: FTC Do Not Call reported calls (numbers as reported by consumers, not verified), NANPA central office code assignments.

All US area codes United States +1 Map of area code 840 — cities & rate centres