Please note: Not every record will have all fields populated.
||Two letter USPS state abbreviation
||Combined Area Code and local number prefix (six digits)
||Area Code (NPA = Numbering Plan Area)
||New Area Code. During the permissive dialling period, the old area code map still
be displayed in the "NPA" field. If blank, then there is no record (yet?) of a split.
If non-blank, then associated NXX is freshly relocated to this new NPA and the NPA in
the "NPA" field (above) would be the old one
||Three digit local number prefix (X=2-9, X=0-9). Generally 201 thru 999.
||Indicates if this NPANXX is in active use ("Active" or "Inactive")
||Latitude of record for the central office
||Longitude of record for the central office
||Latitude for the centroid of the ZIP Code that has the highest frequency of occurrence within the NPANXX
||Longitude for the centroid of the ZIP Code that has the highest frequency of occurrence within the NPANXX
||Local Access Transport Area
||Popular or political name of city
||Offset from GMT (5=East, 6=Central, 7=Mountain, 8=West, etc..)
||Name of county this record resides in.
||The population of the county from the 2010 Census.
||ZIP Code (United States) (five digits)
|ZIP Code Population
Approximate population of the ZIP code.
|Zip Code Freq.
Percent frequency of occurrence of this Zip Code in the NPANXX area.
If = 0, then unknown
If = -1, then the ZIP Code is the most frequent, but % unknown
If = -2, then the ZIP Code is the second most frequent, but % unknown
||Primary use designation. L=Landline, W=Wireless (all wireless; pagers, cellular,
Note that some NXXs may be subdivided between landline and wireless. This is simply
the reported type.
||Version of this product that NXX first appeared. This is not necessarily the NXX
service date, but it should be within 12 months. exception: Since 1994-02-04 was the first version that
included the intro date, then all older NXXs will have an intro date of 1994-02-04 regardless of actual
||1 = NPA recent overlay, blank = Not an overlay
||Ten character Rate Center name for CO. Blank = Rate Center name unknown.
||Census Bureau Names for the metro area of the central office.
||Census Bureau ID numbers for the metro area of the central office.
||Census Bureau FIPS code (ID) for the tract of the central office
||1 = Observes DST (Daylight Saving Time) during the normal DST observance period, 0 =
Does not observe DST at all. Some areas of the country such as AZ (except for the Navajo Nation), HI, GU,
PR, VI, and parts of IN do not observe DST.
||Four-character alphanumeric field identifying the NPA-NXX code-holder and/or service provider.
||The name of the phone company the NPA/NXX is registered to.
||The name of the area this NPA-NXX Covers. This is primarily the city name
but other Alias Names may be used.