Calling Puerto Rico from the United States explained:
- 1 - Country Code for Puerto Rico
- 787/939 - area codes within the NANP
- local phone number - 7 digits
- US to Puerto Rico international dialing format: 1 787 (939) ??? ????
- this US territory is part of the North American Numbering Plan - NANP (calling it works like a US state to state call)