Can I buy my ticket online using a Promotional Voucher? Please check the Terms and Conditions of your voucher. Unfortunately, unless stated otherwise, physical promotional vouchers can only be redeemed on the day against the full gate price. Related articles How do I redeem my Kellogg's Grown Ups Go Free offer? Is my Promotional Voucher valid? Do you offer a Child/Senior/Family discount? How do I redeem my Tesco Clubcard Points? What's new at LEGOLAND Windsor Resort for 2018?