NPA (Number Planning Area), also known as an Area Code, is the three-digit number that identifies the telephone service region. For example, if you have the phone number 555-101-1234, the NPA would be 555.
While the Area Code identifies the telephone service region, it’s possible for a single NPA to be present in more than one rate center. For example, the 305 area code in Florida is present in the following rate centers: Keys, Miami, Homestead, North Dade, and Perrine. If you order a number in NPA 305, you can get a telephone number in any of those rate centers.