I want to get a 16-17 Railcard, for my currently 15yo to travel with after his 16th birthday. I've tried to buy the Railcard and it won't let me as still too young.
The cheap advance tickets are already selling out, but I don't know if I can buy them using the Railcard discount, if I haven't purchased the Railcard yet. Do I have to put in a code during the purchase, or can I just tick the box and sort it out later?