What I have done is when I have taken my cousin there is to teach him before to bend his knees slightly and then you usually should get in for FREE!If you don't try it, you won't know!If not, just be prepared to pay if it does not work but you can take the chance as like me in the mornings, I am tired so admission staff might not notice or be too busy to notice.Hope this helps and have a great day at Chessington & Zoo!