4.2. Validate and Format North American Phone Numbers ...
If you want to limit matches to valid phone numbers according to the North American Numbering Plan, here are the basic rules: Area codes start with a number 2–9, followed by 0–8, and then any third digit. The second group of three digits, known as the central office or exchange code, starts with a number 2–9, followed by any two digits.
DA: 78 PA: 96 MOZ Rank: 19