Dunedin Airport is DUD and London Heathrow Airport is LHR. These codes are created by the International Air Transport Association (IATA) and airlines use them to identify the departing and arrival airports in the flight routes they service. London Gatwick Airport (LGW), London Stansted Airport (STN), London City Airport (LCY), London Luton Airport (LTN), Southampton Eastleigh Airport (SOU) are other airports near this flight route and their unique identifiers/IATA codes.