There are hundreds of airport codes that correspond to airports around the world. One type of airport code is the ICAO code, which is two or four letters long. The first letter in each ICAO signifies what country or region of the world the airport is located.
So what does the letter K mean in an airport code?
When an ICAO code starts with a K, it means the airport is in the contiguous United States. For example, the ICAO code for Los Angeles International Airport in California is KLAX.
But, if you see a four-letter ICAO code where K is not the first letter or see K in another type of airport code of a different length (usually with three letters), it does not necessarily mean the airport is in the US.
This article explains what ICAO codes are and how they differ from IATA codes.
What Is an Icao Code?
An ICAO code is a code assigned to airports all around the world by the International Civil Aviation Organization. The codes are either two or four letters long, and pilots and air traffic controllers use them to communicate with each other.
No two ICAO codes are the same. The first letter of the code signifies where in the world the airport is located, such as the letter K, which represents the 48 lower US states.
But, you may wonder how other ICAO codes are assigned if there are only 26 letters in the alphabet but more than 26 countries. Well, some letters are assigned to a specific region.
For example, the ICAO codes for airports in all of South America start with an S, and airports in Southeast Asia start with a V.
Other letters are assigned to just one country like K is assigned to the United States. Canada uses the letter C, and Australia uses the letter Y.
What Is an Iata Code?
Airports are also assigned an IATA code, which is another way they are recognized and used. You are likely more familiar with IATA codes, as they are the code you see on your tickets, baggage tags, and flight confirmations when you fly. Similar to ICAO codes, no two airports have the same one.
One example of an IATA code is LAX, which is the code for Los Angeles International Airport. The code does not have a letter to signify its region.
Where Do I Find My Icao Code?
If you are looking for an ICAO code in the United States, you can find its IATA code first and add a K in front of the code. All ICAO codes in the US are K + IATA codes. This rule also works for Canadian airports, except they start with a C before their IATA code.
However, not all regions follow this rule. Let’s look back at South America, whose countries have ICAO codes starting with an S. They break it down even further where the second letter in the code corresponds to the country.
For example, airports in Chile start with “SC,” and airports in Paraguay start with “SG.” Not all countries use the letter they start with, like Paraguay. Otherwise, Peru and Paraguay would both start with “SP,” but in reality, only Peru does.
So, you can determine the country and region by looking at the first two letters, but their IATA code is not in the ICAO code, which might make it harder to identify these airports or find their ICAO codes.
If you need to find a specific ICAO or IATA code, Airportcodes.io has a search tool you can use.
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What’s the Difference Between Icao and Iata Codes?
We explained what ICAO codes are, what K in one means, and what IATA codes are, but what’s the difference between ICAO and IATA codes?
ICAO codes are mostly used by professionals like pilots and air traffic controllers, whereas IATA codes are more common among the public.
For example, if you wanted to book a flight from Madrid to Chicago, you would search for flights between MAD and ORD, which are the IATA codes for each city’s major airport.
Then, when you get your boarding pass from the airport, you will see MAD to ORD on the pass as well as on any baggage you check. If you booked a roundtrip ticket, you would have one trip from MAD to ORD and another from ORD to MAD.
Using IATA codes is an easy way for airlines and passengers to identify airports.
IATA and ICAO codes both represent specific airports, and an airport will have one of each code. IATA codes are three letters long, and ICAO is either two or four.
For example, let’s look at the three major New York City airports: Newark, LaGuardia, and John F. Kennedy. Here are their ICAO and IATA codes:
| ICAO Code | IATA Code | |
| Newark | KEWR | EWR |
| LaGuardia | KLGA | LGA |
| John F. Kennedy | KJFK | JFK |
Their ICAO codes all start with a K because they are in the United States. Even if someone did not know that these were all airports in the NYC area, they could tell that all of them are in the United States because they start with K.
However, their IATA codes do not have any similarities, even though they are all within the same region. Unless you already know and recognize these IATA codes, you would not know where they are in the world.
