A personal radio service is any system that allows individuals to operate radio transmitters and receivers for personal purposes with minimal or no special license or individual authorization. Personal radio services exist around the world and typically use light-weight walkie talkie portable radios. The power output, antenna size, and technical characteristics of the equipment are set by regulations in each country. Many regions (for example, the European Union) have standardized personal radio service rules to allow travelers from one country to use their equipment in another country. Examples of standardized services include PMR446 and FM Citizens Band Radio (CB) in the EU and several other countries/regions. 26–27 MHz CB radio is the oldest personal radio service and is used in nearly every country worldwide, with many countries and regions copying the United States 40-channel frequency plan. In many countries, CB radio is less popular due to the availability of other personal radio services that offer shorter antennas and better protection from noise and interference.
Because radio spectrum allocation varies around the world, a personal radio service device may not be usable outside its original area of purchase. For example, US-specification Family Radio Service radios operate on frequencies that in Europe are allocated to fire and emergency services. Operation of a personal radio device that causes interference to other services may result in prosecution. Some personal radio service frequency plans are regionally accepted, for example, the European PMR446 system is available in many countries, and the American FRS/GMRS system's channel plans have been adopted by Canada, Mexico and some countries in South America.