Look Up Another Term

Redirected from: NPA/Nxx

Definition: NPA code

(Numbering Plan Area code) The area code of a telephone number in the NPA system. The first NPA codes used 0 or 1 as the center digit, such as 201, 212, 301, 312, etc., designated as "N0/1X." After July 1, 1995, all digits 0 through 9 are valid as the center digit, designated as "NXX." See NPA and NPA/Nxx.