UK Adverts

Sorry if this has already been asked. How much time are channels allowed for adverts per hour?

A quick Google and Wiki would have told you :

On the commercial channels, the amount of airtime allowed by the UK broadcasting regulator Ofcom for advertising is an overall average of 7 minutes per hour, with limits of 12 minutes for any particular clock hour. (8 minutes per hour between 6pm and 11pm)