With ZIP+4 geocoding, the GEOCODE procedure attempts to match the five-digit ZIP code and ZIP+4 extension from your address data set with the lookup data set. If a ZIP+4 code is not found, the GEOCODE procedure attempts to match the standard five-digit ZIP code. Find geocode for address. Address to Zip+4 ArcGIS Address Locator or batch service? (free?) batch service that will output 9-digit zip ..