Find any 310- phone number in California
The 310 area code is located in Southern California, covering Los Angeles and Orange County. It was created in 1991 in a split from the 213 area code, which previously covered the entire area. The 310 area code is known as an overlay code, meaning that phone numbers can start with either a 213 or a 310 area code while having the same geographic coverage. This system is part of the North American Numbering Plan, which is a uniform system for assigning telephone numbers across the United States, Canada, and several Caribbean countries.
The North American Numbering Plan (NANP) divides the participating countries into region shifts, with each area code typically containing up to 7 million people. Area codes are updated or changed when an existing area code has been filled up with phone numbers, in order to create more available prefixes. California has multiple area codes filled with 10-digit phone numbers, making it one of the most populous states in the United States. The 310 area code is constantly evolving to keep up with projected population increases.