Area Code 840
Area Code 840 is in California
(310 and 424) - (341 and 510)
(415 and 628) - (408 and 669
(714 and 657) - (760 and 442)
(818 and 747) - (820 and 805)
(916 and 279)
Area Code 840 History:
Area code 840 will be put into service as an all services overlay of area code 909. Ten digit dialing (area code + seven digit number) will be necessary in the 909/840 overlay effective January 23, 2021 because different homes in the same geographic area can have the same seven digit phone number but each would have a different area code.
Counties in California within area code 840 include:
Los Angeles County, Riverside County, and San Bernardino County.
Major cities or places in California within area code 909 include:
Area code 840 will serve a portion of eastern Los Angles County, southwest San Bernardino County, and a few communities in Riverside County including the larger cities and communities of Chino, Chino Hills, Claremont, Colton, Diamond Bar, Fontana, Highland, La Verne, Montclair, Ontario, Pomona, Rancho Cucamonga, Redlands, Rialto, San Bernardino, San Dimas, Upland, and Yucaipa in addition to many smaller communities within the area code 840 service area.