United States NPA NXX to ZIP Code Cross-reference

The NPA NXX to ZIP Code Cross-reference database maps telephone area codes and exchanges to 5-digit ZIP Codes. This mapping is based on the geography of the telephone rate center and the ZIP Code boundaries which yields a true representation of the coverage areas.

Often-times there is confusion over what NPA NXX combinations are used within a ZIP Code, this can happen for instance when you try to build the cross-reference using directory listings. The problem with this approach is it generally does not account for foreign exchanges or directory listings based on billing address compared to service address.

NPA NXX to ZIP Code Record Layout  data sample

Field	Data Type	Field Description
NPA	CHAR (3)	The 3-Digit area code.
NXX	CHAR (3)	The 3-digit exchange prefix.
ZIP	CHAR (5)	5-Digit United States ZIP Code.
STATE	CHAR (2)	Two character state abbreviation.
CITY	VARCHAR (128)	Name of city or locale identified by the 5-digit Zip code.
RC	CHAR (10)	LERG abbreviation of the rate center identified by the NPA NXX combination.