The International Air Transport Association (IATA), the international trade body representing most of the world's airlines, uses three-letter location codes for cities and airports. In Toronto, Canada, different codes are used for individual airports and the city itself. Four-letter airport codes have also been established by the International Civil Aviation Organization (ICAO), an agency of the United Nations whose mandate includes ensuring the safe, efficient and orderly evolution of civil aviation.
About Airport Codes
Location identifiers the IATA uses are the most common airport codes the public and travelers see. When traveling, most passengers will see the three-letter airport codes on checked luggage tags, timetables, boarding passes and airline tickets. These codes are also commonly used on airline websites. Codes the ICAO uses are normally used by air traffic controllers as well as by airlines for internal planning and communication. Travelers will normally not see these codes when traveling.
Airport Code Properties
The first – or first and second – letters in ICAO codes represent a specific region. In Canada, most ICAO codes have "C" before the IATA code. For example, the IATA airport code for Calgary International Airport is YYC and CYYC is used by the ICAO. Other codes can be significantly different. For example, Paris Charles de Gaulle Airport is identified as CDG by the IATA. The ICAO identifies the airport with the code LFPG, with "L" representing Europe and "F" representing France.
Toronto Airport Codes
The IATA identifies Toronto Pearson International Airport with the three-letter airport code YYZ. This code is used to identify the airport on airline timetables, tickets and luggage tags. The ICAO identifies Pearson Airport with the four-letter airport code CYYZ, which would be seen and heard at the airport's air traffic control tower and on airline flight plans. Other airports in Toronto are assigned different codes, such as YTZ and CYTZ for Billy Bishop Toronto City Airport.
Toronto City Code
In addition to individual airport codes, the IATA maintains codes to identify airports within a city or metropolitan area. The ICAO does not use unique codes to identify metropolitan areas. The IATA city code for the Toronto metropolitan area is YTO. The code includes Pearson International Airport (YYZ and CYYZ), Billy Bishop Toronto City Airport (YTZ and CTYZ), Buttonville Municipal Airport (YKZ and CYKZ) and John C. Munro Hamilton International Airport (YHM and CYHM).