I recently bought a ticket on trainline using a 16-25 savers railcard. At the gates, a ticket officer asked to see my card and pulled me aside. I said I left it at home and he filled out a form on his IPad and gave me a witness receipt. I then immediately bought a new rail card on trainline and uploaded this to an online Thames link form, as this is what he said to do. I realise that this won’t be valid but I wasn’t sure on what else to do. I know I made a mistake and just panicked in the moment and am more than willing to pay a fine, but just don’t want to go to court. What should I do from here? I know that they will send me a letter most likely, as the rail card will probably be flagged as invalid for this trip, but is there anything I can do to rectify this until then?