Amateur radio callsigns

Amateur radio call signs are allocated to amateur radio operators around the world. The call signs are used to legally identify the station or operator, with some countries requiring the station call sign to always be used and others allowing the operator call sign instead.

The International Telecommunication Union (ITU) allocates call sign prefixes for radio and television stations of all types. Since 1927 these have been used to uniquely identify operators and locate amateur stations within a geographical region or country of the world. Call signs meant for amateur radio follow the ITU's Article 19, specifically 19.68 and 19.69.

Prefixes are assigned internationally, and a separating numeral plus suffix are added by a national body to produce this unique identifier. These prefixes are agreed upon internationally, and are a form of country code. Each country must only assign call signs to its nationals or operators under its jurisdiction that begin with the characters allocated for use in that country or its territories.

In some countries, an operator may also select their own "vanity" call sign that conforms to local laws. Some jurisdictions require a fee to obtain such a vanity call sign; in others, such as the UK, a fee is not required and the vanity call sign may be selected when the license is applied for. The FCC in the U.S. discontinued its fee for vanity call sign applications in September 2015.

An amateur operator's call sign is composed of a prefix, a separating numeral and a suffix.

The prefix can be composed of letters or numbers, the separating numeral is one from 0 to 9, and a suffix is from one to four characters, usually letters.

Examples of call signs and their constituent parts are as follows:

Call signs begin with a one- two- or three-character prefix chosen from a range assigned by the ITU to the amateur's country of operation or other internationally recognized jurisdiction. This is not necessarily always the amateur's country of citizenship. An individual operator is assigned a unique call sign beginning with this prefix and then completed with a separating numeral and suffix.

Beginning at the left of the call sign block, the country chooses one, two or three characters from within the range assigned by the ITU, enough to distinguish its call signs from other jurisdictions.

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