Why can I not book a single from Calais using my vouchers? As a UK based promotion this is the agreement with Tesco. Related articles How do I book with Tesco Clubcard vouchers? How do I check-in if I have booked using Tesco vouchers? Can we give our Tesco vouchers to somebody else? What about people only travelling from Calais to Folkestone? Am I able to purchase a ticket when I arrive?