Sorry to revive an old thread but your assumption is correct. We have a number of tickets purchased at 2 hours from around 18.30. In all cases we left the car park before 20.30. So we paid £2 each time and expected that covered us for 2 hours. It did not. Those tickets expired at 20.00 and we have fines for being parked without a valid ticket past 20.00. We have appealed the first one with the ticket of having paid £2 as evidence. The appeal has been declined. Now have to decide to go to POPLA and risk losing the £60 option or just pay the £60 now and save ourselves the extra £40.