Area codes 787 and (939)(as an overlay), are the local telephonearea codes of Puerto Rico. The (787) area code, or (PUR) was created during a split from the original (809) area code. The split was done on or around March 1996.
When in Puerto Rico, the full area code + seven digit phone number must be dialed. When calling to Puerto Rico from anywhere in the United States or Canada, dial 1 (787) + seven digit phone number.