Our company is working on moving our sales assignments from area codes to ZIP codes, and we need some kind of dataset to help move existing assignments to the new system. Does anyone here know where we could find a complete list of cities (preferably ZIP) by state, along with the associated area code?
USA ZIP Code Areas might be what you are looking for:
This group layer presents five-digit ZIP Code areas used by the U.S. Postal Service to deliver mail more effectively.