Unfortunately Thetrainline.com have an error in their system that can cause them to bill you TWICE for the same ticket. Obviously, if you buy expensive tickets (say for a large group) that could prove rather costly as it may cause you to be overdrawn. In my case I was lucky that the amount was only £14.50. I did not make an error, nothing went wrong with my PC and nothing apparently wrong at their end. I only got one confirmation, one reference number, yet they billed me TWICE. I 'phoned them up, they confirmed one transaction had been made, but they claimed to be unable to confirm if I had been charged twice. I said that quite simply, I have! So I was told to send a copy of my bank statement. I said I'd do this as a file attachment as I do online banking. Fine I was told. But now they demand that I send a paper copy of my statement to them in a letter. And yes, at my expense and time, and despite the fact I don't get paper statements. I've instructed my bank to recover the debt. It seems thetrainline.com:- -treat it's customers with contempt, - pass on all costs of their errors to their customers, - while making it very difficult to get their contact details claiming everything can be done 'online', are actually living in the pre-Internet age when it comes to handling problems - is unaware of it's own accounts - it has no idea who it has billed, and how much (apparently!) Use thetrainline.com at your own risk!!!