Where in North America is area code 310?

Answer 1

This is not a North American area code.
North American area code +1 429 is unassigned. International country code +429 is also unassigned.
North American area code +1 429 is unassigned. International country code +429 is also unassigned.

Answer 2

Area code +1 310 and overlay code +1 424 serve the southwestern part of the Los Angeles metropolitan area, including Santa Monica, Malibu, San Pedro, Torrance, West Los Angeles, Catalina Island, and LAX Airport, plus parts of Beverley Hills and West Hollywood.

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)

Answer 3

Area code 310 serves part of the Los Angeles area, including LAX Airport and Santa Monica, in an overlay with area code 424.

The 310-429 prefix is assigned to Mar Vista. It is mostly cellphones, but there may be some landlines, too.