Now you made me go and look it up!

http://www.adviceguide.org.uk/nw/index/your_world/communications/television_licences.htm#who

See the section entitled "You do not use your television set or video
recorder to watch or record authorised broadcast programmes".


--
Grunf

You can find this on the tv licence website. Straight from the horse's
mouth: http://www.tvlicensing.co.uk/informa...sses.jsp#link5

If you don't use any equipment to receive or record TV programmes, you do
not need a licence. But we still need to hear from you. This is also the
case if you use TV sets for closed circuit monitoring, as a computer monitor
or watching pre-recorded videos only - for example, for training purposes.

You must let us know so that we can update our records to reflect your
status. This will ensure that we do not continue to contact you
unnecessarily.

We may need to confirm your situation by visiting your premises.