There are several reasons why you may be struggling to pre-book your tickets. In this instance you will see an error box.
You may be attempting to book a date or time for which your Pass type isn’t valid (i.e., if you’re a Discovery Passholder and have tried to book a weekend ticket) - if this is the case and you would like to visit on this date, please purchase an Exclusion Day ticket using the links above
You may have exceeded the number of pre-books which you are allowed
Your Pass may have expired and be outside of the validity period