Postal codes in Costa Rica are 5 digit numeric, and were introduced in March 2007, they are associated with and identifies a district. The first digit denotes one of the seven provinces, the 2nd and 3rd refer to the 82 cantons (unique within the province), the 4th and 5th the 488 districts (unique within the canton).[2] The numbers are the same as used by the Instituto Nacional de Estadística y Censos (INEC).[3]