In the United Kingdom, viewing figures – the number of viewers or households watching a television programme – have been recorded by the Broadcasters' Audience Research Board (BARB) since 1981.
Prior to the board's formation, figures were conducted by different means, such as the BBC financing its own audience research, while the ITV companies sub-contracted theirs.
The most watched special event programme of all time on a single channel in the UK is the 1973 wedding ceremony of Princess Anne, shown only on BBC One.
On this measure, the 1996 Christmas edition of Only Fools and Horses is, not including figures for repeats, the most-watched non-documentary programme of all time so far in the United Kingdom.
It is the third most-watched single-showing programme of all time so far on a single channel, behind the 2012 Summer Olympics closing ceremony and the wedding of Princess Anne and Mark Phillips in 1973 (see below).