Description: Returns three digit area codes for any US city/town. Description: Returns all area codes in effect for any state. Description: Returns Mileage, Orig/Dest: City, State, Zip, County LATA and Central Office Code (CLLI) for any US phone exchange. Description: Returns three digit area codes for any US city/town. Description: Returns all area codes in effect for any state. Description: Returns Mileage, Orig/Dest: City, State, Zip, County LATA and Central Office Code (CLLI) for any US phone exchange. Description: Returns three digit area codes for any US city/town. Description: Returns all area codes in effect for any state. Description: Returns Mileage, Orig/Dest: City, State, Zip, County LATA and Central Office Code (CLLI) for any US phone exchange.