Editing IATA airport code (section)

====Cities with multiple commercial airports====
In large metropolitan areas, airport codes are often named after the airport itself instead of the city it serves, while another code is reserved which refers to the city itself which can be used to search for flights to any of its airports. For instance:
* [[Beijing]] (BJS)&nbsp;– [[Beijing Capital International Airport|Capital]] (PEK) and [[Beijing Daxing International Airport|Daxing]] (PKX)
* [[Greater Belo Horizonte|Belo Horizonte]] (BHZ)&nbsp;– [[Belo Horizonte International Airport|Confins]] (CNF) and [[Carlos Drummond de Andrade Airport|Pampulha]] (PLU)
* [[Bucharest]] (BUH)&nbsp;– [[Henri Coandă International Airport|Otopeni]] (OTP) is named after the town of [[Otopeni]] where the airport is located, while the city also has a business airport inside the city limits named [[Aurel Vlaicu International Airport|Băneasa]] (BBU).
* [[Greater Buenos Aires|Buenos Aires]] (BUE)&nbsp;– [[Ministro Pistarini International Airport|Ezeiza]] (EZE) is named after the suburb in [[Ezeiza Partido]] where the airport is located, while [[Aeroparque Jorge Newbery]] (AEP) is in the city proper.
* [[Chicago metropolitan area|Chicago]] (CHI)&nbsp;– [[O'Hare International Airport|O'Hare]] (ORD), named after Orchard Field, the airport's former name, [[Chicago Midway International Airport|Midway]] (MDW), and [[Chicago Rockford International Airport|Rockford]] (RFD).
* [[Jakarta metropolitan area|Jakarta]] (JKT)&nbsp;– [[Soekarno–Hatta International Airport|Soekarno–Hatta]] (CGK) is named after Cengkareng, the [[Cengkareng|district in which the airport is located]], while the city also has another airport, [[Halim Perdanakusuma Airport|Halim Perdanakusuma]] (HLP). JKT used to refer to the city's former airport, [[Kemayoran Airport]], which closed down in the mid-1980s.
* [[Greater London|London]] (LON)&nbsp;– [[Heathrow Airport|Heathrow]] (LHR), [[Gatwick Airport|Gatwick]] (LGW), [[London City Airport|City]] (LCY),<ref name=sky/> [[Stansted Airport|Stansted]] (STN), [[Luton Airport|Luton]] (LTN), and [[Southend Airport|Southend]] (SEN)
* [[Milan metropolitan area|Milan]] (MIL)&nbsp;– [[Milan–Malpensa Airport|Malpensa]] (MXP), [[Linate Airport|Linate]] (LIN), and [[Orio al Serio Airport|Orio al Serio]] (BGY)
* [[Greater Montreal|Montreal]] (YMQ)&nbsp;– [[Montréal–Trudeau International Airport|Trudeau]] (YUL), [[Montréal–Mirabel International Airport|Mirabel]] (YMX), and [[MET – Montreal Metropolitan Airport|Metropolitan]] (YHU)
* [[Moscow metropolitan area|Moscow]] (MOW)&nbsp;– [[Sheremetyevo International Airport|Sheremetyevo]] (SVO), [[Domodedovo International Airport|Domodedovo]] (DME), [[Vnukovo International Airport|Vnukovo]] (VKO), [[Zhukovsky International Airport|Zhukovsky]] (ZIA), business airport [[Ostafyevo International Business Airport|Ostafyevo]] (OSF), and military air base [[Chkalovsky (air base)|Chkalovsky]] (CKL)
* [[New York metropolitan area|New York City]] (NYC)&nbsp;– [[John F. Kennedy International Airport|John F. Kennedy]] (JFK, formerly Idlewild (IDL)), [[La Guardia Airport|LaGuardia]] (LGA), and [[Newark Liberty International Airport|Newark]] (EWR)
* [[Keihanshin|Osaka]] (OSA)&nbsp;–  [[Osaka International Airport|Itami]] (ITM, formerly OSA), [[Kansai International Airport|Kansai]] (KIX), and [[Kobe Airport|Kobe]] (UKB)
* [[Paris metropolitan area|Paris]] (PAR)&nbsp;– [[Orly Airport|Orly]] (ORY), [[Charles de Gaulle Airport|Charles de Gaulle]] (CDG), [[Paris–Le Bourget Airport|Le Bourget]] (LBG), and [[Beauvais–Tillé Airport|Beauvais]] (BVA)
* [[Greater Rio de Janeiro|Rio de Janeiro]] (RIO)&nbsp;– [[Galeão Airport|Galeão]] (GIG) and [[Santos Dumont Airport|Santos Dumont]] (SDU)
* [[Rome metropolitan area|Rome]] (ROM)&nbsp;– [[Leonardo da Vinci–Fiumicino Airport|Fiumicino]] (FCO) and [[Ciampino Airport|Ciampino]] (CIA)
* [[Greater São Paulo|São Paulo]] (SAO)&nbsp;– [[Congonhas Airport|Congonhas]] (CGH), [[São Paulo–Guarulhos International Airport|Guarulhos]] (GRU), and [[Viracopos International Airport|Campinas]] (VCP)
* [[Sapporo]] (SPK)&nbsp;– [[New Chitose Airport|Chitose]] (CTS) and [[Okadama Airport|Okadama]] (OKD)
* [[Seoul Capital Area|Seoul]] (SEL)&nbsp;– [[Incheon Airport|Incheon]] (ICN) and [[Gimpo Airport|Gimpo]] (GMP, formerly SEL)
* [[Stockholm]] (STO)&nbsp;– [[Stockholm–Arlanda Airport|Arlanda]] (ARN), [[Stockholm–Bromma Airport|Bromma]] (BMA), [[Stockholm Skavsta Airport|Nyköping–Skavsta]] (NYO), and [[Stockholm Västerås Airport|Västerås]] (VST)
* [[Tenerife]] (TCI)&nbsp;– [[Tenerife North Airport|Tenerife North]] (TFN) and [[Tenerife South Airport|Tenerife South]] (TFS)
* [[Greater Tokyo Area|Tokyo]] (TYO)&nbsp;– [[Haneda Airport|Haneda]] (HND, formerly TYO) and [[Narita Airport|Narita]] (NRT)
* [[Greater Toronto Area|Toronto]] (YTO)&nbsp;– [[Toronto Pearson International Airport|Pearson]] (YYZ), [[Billy Bishop Toronto City Airport|Billy Bishop]] (YTZ), [[John C. Munro Hamilton International Airport|Hamilton]] (YHM), and [[Region of Waterloo International Airport|Waterloo]] (YKF)
* [[Washington metropolitan area|Washington, D.C.]] (WAS)&nbsp;– [[Dulles International Airport|Dulles]] (IAD), [[Ronald Reagan Washington National Airport|Reagan]] (DCA), and [[Baltimore–Washington International Airport|Baltimore–Washington]] (BWI)

Or using a code for the city in one of the major airports and then assigning another code to another airport:
* [[Almaty]] (ALA)&nbsp;– [[Almaty International Airport|Self-named]] (ALA) and [[Boraldai Airport|Burundai]] (BXJ)
* [[Bangkok Metropolitan Region|Bangkok]] (BKK)&nbsp;– [[Suvarnabhumi Airport|Suvarnabhumi]] (BKK) and [[Don Mueang International Airport|Don Mueang]] (DMK, formerly BKK)
* [[Belfast]] (BFS)&nbsp;– [[Belfast International Airport|International]] (BFS) and [[George Best Belfast City Airport|George Best]] (BHD)
* [[Berlin/Brandenburg Metropolitan Region|Berlin]] (BER)&nbsp;– [[Berlin Brandenburg Airport|Self-named]] (BER). The city also previously had three airports, [[Berlin Tempelhof Airport|Tempelhof]] (THF), [[Berlin Schönefeld Airport|Schönefeld]] (SXF) and [[Berlin Tegel Airport|Tegel]] (TXL), with THF and TXL both now closed. The former Berlin Schönefeld Airport was absorbed into Berlin Brandenburg Airport, with the old Schönefeld terminal becoming ''Terminal 5''.
* [[Chengdu]] (CTU)&nbsp;– [[Chengdu Shuangliu International Airport|Shuangliu]] (CTU), [[Chengdu Tianfu International Airport|Tianfu]] (TFU), and [[Chengdu Huaizhou International Airport|Huaizhou]] [[:zh:成都淮州机场|(HZU; zh)]]<ref>{{Cite web|title=Airline and Location Code Search|url=https://www.iata.org/en/publications/directories/code-search/|access-date=14 January 2022|website=IATA.org|publisher=International Air Transport Association}}</ref>
* [[Colombo]] (CMB)&nbsp;– [[Bandaranaike International Airport|Bandaranaike]] (CMB) and [[Ratmalana Airport|Ratmalana]] (RML)
* [[Dakar]] (DKR)&nbsp;– [[Léopold Sédar Senghor International Airport|Senghor]] (DKR) and [[Blaise Diagne International Airport|Diass]] (DSS)
* [[Dallas–Fort Worth metroplex|Dallas–Fort Worth]] (DFW)&nbsp;– [[Dallas/Fort Worth International Airport|Self-named]] (DFW), [[Dallas Love Field|Love Field]] (DAL), [[Fort Worth Meacham International Airport|Meacham]] (FTW), [[Fort Worth Alliance Airport|Alliance]] (AFW), and [[Addison Airport|Addison]] (ADS)
* [[Dubai]] (DXB)&nbsp;– [[Dubai International Airport|Self-named]] (DXB) and [[Al Maktoum International Airport|Al Maktoum]] (DWC)
* [[Goa]] (GOI) –  [[Dabolim Airport]] (GOI) and [[Manohar International Airport]] (GOX)
* [[Glasgow]] (GLA)&nbsp;– [[Glasgow Airport|International]] (GLA) and [[Glasgow Prestwick Airport|Prestwick]] (PIK)
* [[Greater Houston|Houston]] (HOU)&nbsp;– [[William P. Hobby Airport|Hobby]] (HOU), [[George Bush Intercontinental Airport|George Bush Intercontinental]] (IAH), and [[Ellington Airport (Texas)|Ellington]] (EFD)
* [[Istanbul]] (IST)&nbsp;– [[Istanbul Airport|Self-named]] (IST), [[Istanbul Sabiha Gökçen International Airport|Sabiha Gökçen]] (SAW), and [[Istanbul Atatürk Airport|Atatürk]] (ISL, formerly IST)
* [[Johannesburg]] (JNB)&nbsp;– [[O. R. Tambo International Airport|O. R. Tambo (formerly Jan Smuts)]] (JNB) and [[Lanseria International Airport|Lanseria]] (HLA)
* [[Greater Kuala Lumpur|Kuala Lumpur]] (KUL)&nbsp;– [[Kuala Lumpur International Airport|Sepang]] (KUL) and [[Sultan Abdul Aziz Shah Airport|Subang]] (SZB, formerly KUL)
* [[Kyiv metropolitan area|Kyiv]] (IEV)&nbsp;– [[Kyiv International Airport (Zhuliany)|Zhuliany]] (IEV) and [[Boryspil International Airport|Boryspil]] (KBP)
* [[Greater Los Angeles|Los Angeles]] (LAX)&nbsp;– [[Los Angeles International Airport|Self-named]] (LAX), [[San Bernardino International Airport|San Bernardino]] (SBD), [[Ontario International Airport|Ontario]] (ONT), [[John Wayne Airport|Orange County]] (SNA), [[Van Nuys Airport|Van Nuys]] (VNY), [[Palmdale Regional Airport|Palmdale]] (PMD), [[Long Beach Airport|Long Beach]] (LGB), and [[Hollywood Burbank Airport|Burbank]] (BUR)
* [[Medellín]] (MDE)&nbsp;– [[José María Córdova International Airport|José María Córdova]] (MDE) and [[Olaya Herrera Airport|Olaya Herrera]] (EOH)
* [[Mexico City]] (MEX)&nbsp;– [[Mexico City International Airport|Self-named]] (MEX) and [[Felipe Ángeles International Airport|Felipe Ángeles]] (NLU)
* [[Melbourne]] (MEL)&nbsp;– [[Melbourne Airport|Tullamarine]] (MEL), [[Essendon Airport|Essendon]] (MEB), and [[Avalon Airport|Avalon]] (AVV)
* [[Miami metropolitan area|Miami]] (MIA)&nbsp;– [[Miami International Airport|Self-named]] (MIA), [[Fort Lauderdale-Hollywood International Airport|Fort Lauderdale]] (FLL), and [[Palm Beach International Airport|West Palm Beach]] (PBI)
* [[Chūkyō metropolitan area|Nagoya]] (NGO)&nbsp;– [[Chubu Centrair International Airport|Centrair]] (NGO) and [[Nagoya Airfield|Komaki]] (NKM, formerly NGO)
* [[San Diego]]&nbsp;– [[San Diego International Airport|Self-named]] (SAN) and [[Tijuana International Airport|Tijuana]] (TIJ). TIJ is physically located in [[Tijuana]], Mexico, but offers access directly to and from the US via the [[Cross Border Xpress]].
* [[San Francisco Bay Area|San Francisco]] (SFO)&nbsp;– [[San Francisco International Airport|Self-named]] (SFO), [[Oakland International Airport|Oakland]] (OAK), [[San Jose International Airport|San Jose–Mineta]] (SJC), and [[Charles M. Schulz–Sonoma County Airport|Sonoma–Schulz]] (STS)
* [[Seattle metropolitan area|Seattle]] (SEA)&nbsp;– [[Seattle–Tacoma International Airport|Tacoma (Sea–Tac)]] (SEA), [[Boeing Field]] (BFI), and [[Paine Field]] (PAE)
* [[Shanghai]] (SHA)&nbsp;– [[Shanghai Pudong International Airport|Pudong]] (PVG) and [[Shanghai Hongqiao International Airport|Hongqiao]] (SHA)
* [[Taipei–Keelung metropolitan area|Taipei]] (TPE)&nbsp;– [[Taoyuan International Airport|Taoyuan (formerly Chiang Kai-shek)]] (TPE) and [[Taipei Songshan Airport|Songshan]] (TSA, formerly TPE)
* [[Tehran]] (THR)&nbsp;– [[Tehran Imam Khomeini International Airport|Imam Khomeini]] (IKA) and [[Mehrabad International Airport|Mehrabad]] (THR)

When different cities with the same name each have an airport, they need to be assigned different codes. Examples include:
* [[Juan Santamaría International Airport]] (SJO) is in [[Alajuela Province|Alajuela]], serving the capital [[San José, Costa Rica|San José de Costa Rica]]. While [[Norman Y. Mineta San Jose International Airport]] (SJC) is in [[San Jose, California]], the United States.
* [[Birmingham–Shuttlesworth International Airport]] (BHM) is in [[Birmingham, Alabama]], the United States and [[Birmingham Airport]] (BHX) is in [[Birmingham]], England, United Kingdom.
* [[Portland International Jetport]] (PWM) is in [[Portland, Maine]], while [[Portland International Airport]] (PDX) is in [[Portland, Oregon]].
* [[Manchester Airport]] (MAN) is in [[Manchester]], England, United Kingdom, while [[Manchester–Boston Regional Airport|Manchester-Boston Regional Airport]] (MHT) is in [[Manchester, New Hampshire|Manchester]], [[New Hampshire]], United States.
* [[Arturo Merino Benítez International Airport]] (SCL) is in [[Santiago]], Chile; while [[Antonio Maceo Airport]] (SCU) is in [[Santiago de Cuba|Santiago]], Cuba; [[Santiago–Rosalía de Castro Airport]] (SCQ) is in [[Santiago de Compostela]], Spain; and [[Cibao International Airport]] (STI) serves [[Santiago de los Caballeros]], Dominican Republic.

Sometimes, a new airport is built, replacing the old one, leaving the city's new "major" airport (or the only remaining airport) code to no longer correspond with the city's name. The original airport in Nashville, Tennessee, was built in 1936 as part of the Works Progress Administration and called Berry Field with the designation, BNA. A new facility known as Nashville International Airport was built in 1987 but still uses BNA. This is in conjunction to rules aimed to avoid confusion that seem to apply in the United States, which state that "the first and second letters or second and third letters of an identifier may not be duplicated with less than 200 [[nautical mile]]s separation."<ref name=sky/> Thus, Washington, D.C. area's three airports all have radically different codes: IAD for [[Washington Dulles International Airport|Washington–Dulles]], DCA for [[Ronald Reagan Washington National Airport|Washington–Reagan]] (District of Columbia Airport), and BWI for [[Baltimore Airport|Baltimore]] (Baltimore–Washington International, formerly BAL).<ref name=sky/> Since HOU is used for [[William P. Hobby Airport]], the new [[Houston–Intercontinental]] became IAH.<ref name=sky/> The code BKK was originally assigned to [[Don Mueang International Airport|Bangkok–Don Mueang]] and was later transferred to [[Suvarnabhumi Airport]], while the former adopted DMK. The code ISK was originally assigned to [[Gandhinagar Airport]] (Nashik's old airport) and later on transferred to [[Nashik Airport|Ozar Airport]] (Nashik's current airport). [[Shanghai Hongqiao International Airport|Shanghai–Hongqiao]] retained the code SHA, while the newer [[Shanghai Pudong International Airport|Shanghai–Pudong]] adopted PVG. The opposite was true for [[Berlin]]: the airport [[Berlin Tegel Airport|Berlin–Tegel]] used the code TXL, while its smaller counterpart [[Berlin Schönefeld Airport|Berlin–Schönefeld]] used SXF; the [[Berlin Brandenburg Airport]] has the airport code BER, which is also part of its branding. The airports of [[Hamburg Airport|Hamburg]] (HAM) and [[Hannover Airport|Hannover]] (HAJ) are less than {{convert|100|nmi|km|sp=us}} apart and therefore share the same first and middle letters, indicating that this rule might be followed only in Germany.