Andy’s agent for cartoon work is Gordon Wise at Curtis Brown. You can contact him via this page..
His agent for scriptwriting is Lily Williams at Curtis Brown. You can contact her via this page..
If you’d Andy to appear at a festival or school to talk about his children’s books, your best bet is to contact Emily Thomas at Hachette Children’s via Emily.Thomas@hachettechildrens.co.uk.
Andy also has a publicly available email where you can contact him directly. But before you do, please look at this FAQ post to see if your question is covered there. If it’s not, please get in touch using email@example.com and a link to that is here.