If any current season ticket holders are experiencing problems adding next seasons subscription to their existing card using the online payment method, then I should call it a day and go to the box office as I did tonight. It would appear that the cards are being renewed and on purchase will be available for collection or receipt by post in July. This would explain why on-line it will not allow you to add to your existing.
Did mine online no problem. It does mention that new cards are going to be issued and be available from early July.