Getting zip-code + 4 from latitude/longitude

Question

Does anyone know the best way to use the iPhone location services (lat/long) to determine the zip code+4 of the user? Does MKReverseGeocoder have the ability to pull back zip+4?

Thanks!

-tony

Answer 1

You may be able to use a free Reverse Geocoding service to do this for you.

Google has such a service: http://code.google.com/apis/maps/documentation/services.html#ReverseGeocoding

Alternately, this Google Groups post has a listing of other Reverse Geocoding services: http://groups.google.com/group/Google-Maps-API/web/resources-non-google-geocoders?pli=1

Answer 2

My favorite place to go for anything having to do with geocoding is geonames.org.

Answer 3

If you read the documentation from Apple, you'll see that the MKPlacemark that MKReverseGeocoder only returns a five-digit zip code. You will likely have to use an outside reverse geocoder as described in the other comments to get the extra four digits.

Answer 4

The $19 Geo database at http://semaphorecorp.com/zp4/geo.html can give you the nearest ZIP+4 for a lat/long input. The ZIP+4 database changes monthly. Note that most ZIP+4 cover all addresses on one side of a street for one block.