With lots of hardware (radios) but no one producing the software (programmes), the UK Government in the 1920s had to decide how to fund radio broadcasting.
The decision made was that the fledgling British Broadcasting Company would be funded not by commercials but by the introducuction of a compulsory radio licence. Anyone wanting to listen to radio programmes had to have one ... a situation that lasted until 1971!
This website looks at the history of the UK Radio Licence and includes many examples of early licences and associated memorabilia
Radio Licence history had over 16500 unique visitors during 2007.