In all countries, amateur radio operators are required to pass a licensing exam displaying knowledge and understanding of key concepts. In response, hams are granted operating privileges in larger segments of the radio frequency spectrum using a wide variety of communication techniques with higher power levels permitted. This practice is in contrast to unlicensed personal radio services such as CB radio, Multi-Use Radio Service, or Family Radio Service/PMR446 that require type-approved equipment restricted in frequency range and power.
In many countries, amateur licensing is a routine civil administrative matter. Amateurs are required to pass an examination to demonstrate technical knowledge, operating competence and awareness of legal and regulatory requirements in order to avoid interference with other amateurs and other radio services. There are often a series of exams available, each progressively more challenging and granting more privileges in terms of frequency availability, power output, permitted experimentation, and in some countries, distinctive callsigns. Some countries such as the United Kingdom and Australia have begun requiring a practical training course in addition to the written exams in order to obtain a beginner's license, called a Foundation License.
Amateur radio licensing in the United States serves as an example of the way some countries award different levels of amateur radio licenses based on technical knowledge. Three sequential levels of licensing exams (Technician Class, General Class and Amateur Extra Class) are currently offered, which allow operators who pass them access to larger portions of the Amateur Radio spectrum and more desirable callsigns.
Many people start their involvement in amateur radio by finding a local club. Clubs often provide information about licensing, local operating practices and technical advice. Newcomers also often study independently by purchasing books or other materials, sometimes with the help of a mentor, teacher or friend. Established amateurs who help newcomers are often referred to as "Elmers" within the ham community. In addition, many countries have national amateur radio societies which encourage newcomers and work with government communications regulation authorities for the benefit of all radio amateurs. The oldest of these societies is the Wireless Institute of Australia, formed in 1910; other notable societies are the Radio Society of Great Britain, the American Radio Relay League, Radio Amateurs of Canada, the New Zealand Association of Radio Transmitters and South African Radio League. (See Category:Amateur radio organizations)
Upon licensing, a radio amateur's national government issues a unique callsign to the radio amateur. The holder of a callsign uses it on the air to legally identify the operator or station during any and all radio communication. In certain jurisdictions, an operator may also select a "vanity" callsign although these must also conform to the issuing government's allocation and structure used for Amateur Radio callsigns. Some jurisdictions, such as the U.S., require that a fee be paid to obtain such a vanity callsign; in others, such as the UK, a fee is not required and the vanity callsign may be selected when the license is applied for.
Callsign structure as prescribed by the ITU, consists of three parts which break down as follows, using the callsign ZS1NAT as an example:
ZS – Shows the country from which the callsign originates and may also indicate the license class. (This callsign is licensed in South Africa, and is CEPT Class 1).
1 – Gives the subdivision of the country or territory indicated in the first part (this one refers to the Western Cape).
NAT – The final part is specific to the holder of the license, identifying that person specifically.
Many countries do not follow the ITU convention for the numeral. In the United Kingdom the calls G2xxx, G3xxx, and G6xx may be issued to stations that are geographically right next to each other. In the United States, the numeral indicates the geographical district the holder resided in when the license was issued. Prior to 1978, US hams were required to obtain a new callsign if they moved out of their geographic district.
Also, for smaller entities, a numeral may be part of the country identification. For example, VP2xxx is in the British West Indies (subdivided into VP2Exx Anguilla, VP2Mxx Monserrat, and VP2Vxx British Virgin Islands), VP5xxx is in the Turks and Caicos Islands, VP6xxx is on Pitcairn Island, VP8xxx is in the Falklands, and VP9xxx is in Bermuda.
Anybody can look up who a specific United States callsign belongs to using the FCC's license search database. Information may be available for other jurisdictions on websites such as Callbook.