International paperwork for a cat is a chain, and it breaks at its weakest link: a vaccination given before the microchip was implanted, so it falls outside the sequence the destination counts, a certificate issued a day outside the accepted window, or an airline that was never told a cat would be travelling. Work through the chain in the order officials and carriers will examine it.
Identity and vaccination: the foundation documents
Your cat needs a working microchip, and its number must match every document that follows exactly, so have it scanned before you build anything else. The vaccination record, including rabies vaccination where the destination requires it, is read against that chip and against timing rules the destination sets, which is why vaccinations connected to travel are sequenced carefully rather than simply being current. Some destinations add further requirements, such as specific treatments before departure or blood testing with its own waiting logic, and those can take far longer to arrange than the flight booking itself.
The health certificate and destination permits
Most destinations require a health certificate: a veterinarian examines the cat and signs the official form the destination prescribes, within the window that destination accepts before travel. Some countries also require an import permit arranged in advance, an official endorsement of the certificate by a government vet, or paperwork completed in a particular language or format. Start from the destination government's own published rules for bringing in a cat, and treat social media accounts of other people's trips as leads to verify, never as the specification.
The airline's separate layer of approval
Government permission does not put a cat on a plane. Each airline sets its own conditions: whether cats may travel in the cabin or the hold, carrier dimensions, breed or age restrictions, a booking process for the pet space, and documents it wants to see at check-in. Confirm the cat is actually booked onto your specific flights, including any connecting legs on different carriers, and keep the airline's written confirmation with the certificates. A perfectly documented cat can still be refused at the desk if the pet booking was assumed rather than made.
Originals, copies, and check-in day handling
Carry the originals in your hand luggage, never in checked baggage, and keep a complete second set as photographs on your phone plus a printed copy held by someone staying at home. Lay the documents in the order they will be requested: airline confirmation first, certificate next, vaccination and permit papers behind it. At each desk, hand over the specific document asked for rather than the whole folder, and check every page is returned before you walk away, because a certificate retained at an intermediate check-in leaves you undocumented for the border that actually matters.
Plan the return before you fly out
Re-entry to your home country has its own rules, and a cat that left legally can still face questions, quarantine risk, or refused entry on return if those were never checked. Build both directions' paperwork as one project, with copies stored separately from the originals you carry. Travelling with the whole file organised in KinsLe's Pet Passport means the chip record, certificates, permits, and airline confirmation sit together as one packet, ready for each inspection point instead of being reassembled from emails at every desk.