UN/LOCODE

UN/LOCODE, the United Nations Code for Trade and Transport Locations, is a geographic coding scheme developed and maintained by United Nations Economic Commission for Europe (UNECE). UN/LOCODE assigns codes to locations used in trade and transport with functions such as seaports, rail and road terminals, airports, Postal Exchange Office and border crossing points. The first issue in 1981 contained codes for 8,000 locations. The version from 2011 contained codes for about 82,000 locations.

Structure

UN/LOCODEs have five characters. The first two characters are letters. They code a country by the table defined in ISO 3166-1 alpha-2. The three remaining characters code a location within that country. Letters are preferred, but if necessary digits 2 through 9 may be used, excluding "0" and "1" to avoid confusion between "O" and "0" and between "I" and "1".

For each country there can be a maximum of 26*26*26 = 17 576 entries, using only letters, or 34*34*34 = 39 304 entries using letters and digits.