I have a Kellogg's Cereal pack, how do I pre-book my ticket? Your Kellogg’s cereal pack will have a unique code printed inside. Pre-book your tickets by visiting www.merlinfun.co.uk and follow the booking steps. Related articles I have a Kellogg’s snack pack voucher (e.g Fruit Winders, Rice Krispie Squares), how do I pre-book my ticket? I have a promotional voucher, how can I pre-book? When are the busiest and quietest times to visit? I have a promotional offer, how do I use this online? I have a Sun 2 4 1 voucher, how do I pre-book?