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Area Code 840 Location & Details

State / Region: California • Country: United States

Major Cities Covered: San Bernardino, Fontana, Ontario, Rancho Cucamonga, Pomona, Rialto, Chino, Upland, Chino Hills, Redlands

Standard Dial Format
+1 (840) XXX-XXXX
Country Code: +1 (NANP Format)
What State is Area Code 840?
CaliforniaState Hub →
Country Territory
United States
840 Area Code Time Zone
Pacific
840 Overlay Codes
909

Area Code 840 Geographic Map

Interactive location bounds and coverage area for California (Pacific Timezone)

Lat: 34.07° • Lng: -117.48°
📍 Geographic Center: CaliforniaMap data © OpenStreetMap contributors

Where is Area Code 840 Located?

Telephone area code 840 is assigned to California in United States. It serves cities and metropolitan communities including San Bernardino, Fontana, Ontario, Rancho Cucamonga, Pomona, Rialto, Chino, Upland, Chino Hills, Redlands.

Historical Context & Area Code Overlay Information:840 serves California (United States).

For local and long-distance calls within area code 840, standard 10-digit dialing (840) XXX-XXXX applies.

Who Called Me from Area Code 840?

Received an unknown call, missed call, or text scam from area code 840? Here is how to trace who is calling from 840 area code and verify unknown numbers safely:

1.
Identify Missed Calls & Voicemails:

Legitimate contacts usually leave a detailed voicemail or caller ID record.

2.
Watch Out for Neighbor Spoofing:

Robocallers often fake incoming caller ID numbers using your local 840 prefix to boost pick-up rates.

3.
Reverse Phone Lookup Area Code 840:

Search public white-pages or use caller intelligence guides before returning unfamiliar calls.

Learn How Reverse Phone Lookups Work→

How to Call Area Code 840 & Dialing Format

When placing a phone call to a number in area code 840, follow the correct dialing format depending on your calling location:

  • Calling from inside the US / Canada (+1): Dial 1 + (840) + 7-digit number.
  • Calling from an international location outside +1: Dial your country's international exit code (e.g. 011 in US or + on mobile) + 1 + 840 + 7-digit number.
  • Do I need to dial area code 840 for local calls? Yes, 10-digit dialing (area code + line number) is mandatory across North American telephone networks.

Top Cities & Municipalities Served in Area Code 840

Urban centers, census places, and communities within the +1-840 calling area

24 Major Cities Listed
City NameCountyPopulation% of 840 Pop
San BernardinoOrange County222,04411.7%
FontanaOrange County221,22311.7%
OntarioOrange County187,0139.9%
Rancho CucamongaOrange County177,8569.4%
PomonaOrange County147,8077.8%
RialtoOrange County106,5545.6%
ChinoOrange County96,9575.1%
UplandOrange County79,4464.2%
Chino HillsOrange County77,5194.1%
RedlandsOrange County74,1283.9%
EastvaleOrange County70,5943.7%
HighlandOrange County57,6143.0%
YucaipaOrange County54,9532.9%
ColtonOrange County53,3832.8%
Diamond BarOrange County51,8842.7%
MontclairOrange County37,5632.0%
ClaremontOrange County35,8381.9%
San DimasOrange County32,9781.7%
La VerneOrange County30,1781.6%
WalnutOrange County27,3161.4%

Counties Covered by Area Code 840

Geographic county distribution and population coverage across California

County NameTotal Population% of 840 Area% of County
Orange County3,158,02799.7%60%
San Bernardino County2,218,7640.3%0%

☎️Area Code 840 Exchange Prefixes & Carriers

Showing 50 of 139 central office 3-digit prefixes and assigned telecom carriers

36% Landline44% Wireless20% VoIP
PrefixLine UsageRate CenterAssigned CarrierAssign Date
(840) 200-📞LandlineCHINOFRACTEL, LLC01/04/2021
(840) 201-📱WirelessFONTANANEW CINGULAR WIRELESS PCS, LLC03/11/2021
(840) 202-📱WirelessPOMONANEW CINGULAR WIRELESS PCS, LLC07/29/2021
(840) 203-📱WirelessS BERNDINONEW CINGULAR WIRELESS PCS, LLC07/29/2021
(840) 204-📱WirelessS BERNDINONEW CINGULAR WIRELESS PCS, LLC07/29/2021
(840) 205-💻VoIPCLAREMONTBANDWIDTH.COM CLEC, LLC - CA10/27/2021
(840) 206-📱WirelessCHINONEW CINGULAR WIRELESS PCS, LLC08/10/2021
(840) 207-📱WirelessARROWHEADT-MOBILE USA, INC.10/28/2021
(840) 208-💻VoIPCLAREMONTBANDWIDTH.COM CLEC, LLC - CA02/22/2022
(840) 209-📱WirelessARROWHEADT-MOBILE USA, INC.08/31/2021
(840) 210-📱WirelessFONTANAT-MOBILE USA, INC.12/14/2021
(840) 211-📞LandlineCAMULTIPLE OCN LISTINGN/A
(840) 212-📱WirelessCHINOT-MOBILE USA, INC.11/15/2021
(840) 213-📱WirelessREDLANDST-MOBILE USA, INC.08/12/2022
(840) 214-📱WirelessMARSHALLT-MOBILE USA, INC.08/12/2022
(840) 215-📱WirelessHIGHLANDT-MOBILE USA, INC.02/28/2022
(840) 216-📱WirelessARROWHEADT-MOBILE USA, INC.03/01/2022
(840) 217-📱WirelessFONTANAT-MOBILE USA, INC.09/02/2022
(840) 218-📱WirelessCHINOCELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA10/10/2022
(840) 219-📱WirelessCALIMESAT-MOBILE USA, INC.09/13/2021
(840) 220-💻VoIPRIALTOBANDWIDTH.COM CLEC, LLC - CA09/13/2022
(840) 221-📞LandlineS BERNDINOHD CARRIER LLC10/21/2022
(840) 222-📞LandlineS BERNDINOFRACTEL, LLC12/24/2020
(840) 223-💻VoIPCALIMESABANDWIDTH.COM CLEC, LLC - CA10/24/2022
(840) 224-📱WirelessS BERNDINONEW CINGULAR WIRELESS PCS, LLC12/06/2022
(840) 225-📱WirelessPOMONANEW CINGULAR WIRELESS PCS, LLC03/10/2023
(840) 226-💻VoIPPOMONAONVOY, LLC - CA04/07/2023
(840) 227-📱WirelessS BERNDINOCELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA04/13/2023
(840) 228-📱WirelessCOLTONCELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA04/17/2023
(840) 229-📱WirelessCLAREMONTCELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA04/18/2023
(840) 230-📞LandlinePOMONABOOST SUBSCRIBERCO L.L.C.05/30/2023
(840) 231-📱WirelessPOMONAT-MOBILE USA, INC.05/31/2023
(840) 232-📱WirelessFONTANAT-MOBILE USA, INC.06/09/2023
(840) 233-📱WirelessARROWHEADT-MOBILE USA, INC.07/13/2023
(840) 234-📞LandlineARROWHEADFRACTEL, LLC04/18/2021
(840) 235-📞LandlineCOLTONCOMMIO, LLC08/11/2023
(840) 236-💻VoIPCLAREMONTONVOY, LLC - CA09/19/2023
(840) 237-💻VoIPONTARIOONVOY, LLC - CA09/19/2023
(840) 238-📱WirelessPOMONANEW CINGULAR WIRELESS PCS, LLC09/26/2023
(840) 239-💻VoIPFONTANAONVOY, LLC - CA10/02/2023
(840) 240-💻VoIPDIAMONDBARONVOY, LLC - CA11/18/2022
(840) 241-💻VoIPRIALTOONVOY, LLC - CA10/02/2023
(840) 242-💻VoIPUPLANDONVOY, LLC - CA10/02/2023
(840) 243-📱WirelessPOMONAT-MOBILE USA, INC.10/10/2023
(840) 244-📱WirelessDIAMONDBART-MOBILE USA, INC.10/16/2023
(840) 245-📱WirelessREDLANDST-MOBILE USA, INC.10/18/2023
(840) 246-📱WirelessETIWANDAT-MOBILE USA, INC.11/01/2023
(840) 247-📱WirelessHIGHLANDT-MOBILE USA, INC.11/08/2023
(840) 248-📱WirelessFONTANAT-MOBILE USA, INC.12/05/2023
(840) 249-📱WirelessMARSHALLT-MOBILE USA, INC.12/07/2023

Frequently Asked Questions about Area Code 840

Where is area code 840 located?

Area code 840 is located in California (United States), serving cities like San Bernardino, Fontana, Ontario, Rancho Cucamonga, Pomona, Rialto, Chino, Upland, Chino Hills, Redlands.

What timezone is area code 840?

Area code 840 operates in the Pacific timezone.

What state is area code 840?

Area code 840 is assigned to the state / telecom territory of California.

Is area code 840 a scam or dangerous?

Area code 840 is an official geographic area code for California. However, beware of robocaller spoofing.

California State Area Codes

View complete directory of telephone area codes assigned to California.

Explore California Directory

Get a 840 Business Phone Number

How to acquire a virtual phone number or business line with area code 840 for local customer trust in California.

Get 840 Business Number
🛡️ Scam & Safety Directory

Check high-risk international callback scam area codes and robocall warning databases.

Scam Area Codes 2026

Overlay & Nearby Area Codes for California

Explore neighboring telecom prefixes sharing geographical boundaries with area code 840.

909
Pacific
Area Code 909
San Bernardino, Fontana, Ontario, Rancho Cucamonga, Pomona, Rialto, Chino, Upland, Chino Hills, Redlands
209
Pacific
Area Code 209
Stockton, Modesto, Tracy, Merced, Manteca, Turlock, Lodi, Los Banos, Ceres, Lathrop
213
Pacific
Area Code 213
Los Angeles, Montebello, Commerce, Vernon
279
Pacific
Area Code 279
Sacramento, Elk Grove, Roseville, Folsom, Rancho Cordova, Citrus Heights, Rocklin, Lincoln, West Sacramento, Loomis
310
Pacific
Area Code 310
Torrance, Inglewood, Carson, Compton, Santa Monica, South Gate, Hawthorne, Redondo Beach, Lynwood, Gardena
323
Pacific
Area Code 323
Los Angeles, South Gate, Montebello, Huntington Park, Bell Gardens, Commerce, Vernon