I'll be using 2FOR1 vouchers and I have one question regarding this. Namely: can I book the attraction I'm planning to visit online and then show the voucher to get the discount? Or the voucher applies only to tickets bought on the spot? For example, can I book a Wembley tour online, have a receipt saying I am to pay 30GBP and then, at the stadium, get those tickets for 15GBP? Can I also book Tussaud's and so on in that manner?