Before accepting any booking you should read the booking details to ensure that you fulfil the booking.
However we understand mistakes can happen from time to time. The best thing to do is cancel the booking straight away. Depending on the pick up time you may not receive a cancellation fee straight away. See When does a cancellation fee apply?
The earlier you cancel the more chance we have of finding the passenger another driver to complete the booking, so please cancel as soon as you realise you have accepted the booking.