First things first: talk to your vet and find out if they can issue them. If they can’t, ask their advice on what other vets in the area might be able to help. Once you’ve found a vet who can issue it, you need to take your cat(s) to the vet no more than ten days in advance of your trip. When you go, you’ll also need to take proof of your cat’s microchipping date and their vaccination history.
If everything’s in order, the vet will sign your Animal Health Certificate, and at that point it’s valid for entering the EU or travelling between GB and NI for the next ten days, and for coming home within the next four months. If you’re planning to visit multiple countries, great news: it’ll also be valid for the next four months for onward travel within the EU.
Don’t forget: you need an Animal Health Certificate for each time you travel with a cat, so you can’t just use the same one you used for your last holiday.