Originally Posted by
stifle
Yes – but you'll need to buy online and collect a physical credit card sized ticket as this journey cannot be ticketed any other way. I am not sure whether there are any facilities to issue such a ticket at Heathrow. There used to be a collection machine at the central coach station and another on the T5 arrivals floor, but I have no idea if they are still there or working.
Thanks. I was planning to pick up the ticket from another train station a few days before anyway but it is indeed an important consideration to bear in mind for anybody planning to do this.