The Consumer Contracts Regulations - which came into force on 13 June 2014 and implement the Consumer Rights Directive - give you rights when shopping online, so you’re covered if things go wrong.
Your right to cancel an order for goods starts the moment you place your order and ends 14 days from the day you receive your goods. If your order consists of multiple goods, the 14 days runs from when you get the last of the batch. This 14 day period is the time you have to decide whether to cancel, you then have a further 14 days to actually send the goods back.
If you request a service starts straightaway
In this instance you will still have the right to cancel, but you must pay for the value of the service that is provided up to the point you cancel.
If the service is provided in full within 14 days The right to cancel can be lost during the cancellation period if the service is provided in full before the 14 days elapses.