Alongside the EU-wide chip, vaccine and passport rules, Sweden imposes a requirement that doesn't appear anywhere else in this guide: under Tullverket's own regulations, a person bringing a dog or cat into Sweden from another EU country for non-commercial reasons (travelling with your own pet, not trading or selling it) must report the import to Tullverket, Swedish customs.

Tullverket's regulation sets out two ways to do this. You can report orally to a customs officer at a customs post or office when you arrive, or you can file the report online in advance through a form on Tullverket's own website. If you file online beforehand, you don't need to report again on arrival — you simply keep the registration number you're issued and show it if a customs officer asks for it.

This isn't a document you'll be refused entry over if you forget it on the day, but it is a genuine legal reporting obligation, separate from anything an EU pet passport covers, and filing it online before you travel is a far smoother experience than trying to find the right customs desk with a dog on a leash and a ferry about to depart.