Existing customers
If you have been given a promotional code, sign in to your account, go to 'my promotions' and enter the code to redeem it before making a booking. 

You can also add a code at the Booking Summary when you're checking out — don't forget to click apply!

New customers

If you are a new customer and have been given a sign-up or referral code then this will need to be entered on the sign-up form only (see below). Unfortunately, it cannot be redeemed once the account has been created.