Licensing radios (and later TV's) has been around since the earliest days of broadcasting in Britain. This was supposed to be the funding source for the BBC though I suspect it pays for a lot more than just the BBC now. Originally, the tax was paid on a per set basis, paid as part of the price of the set. Now, it appears to be on a per household basis, paid annually. Ain't socialism wonderful!
Only if you actually own a TV. If you don't, as I don't, no fee is payable.