Travel documentation for cats varies considerably depending on destination, airline, and mode of transport, and starting this research well before your trip date matters given how many requirements have specific advance timing windows that can't be compressed if discovered too late.
Health certificates: the most universally required document
Most airlines and destinations require a health certificate issued by a licensed vet within a specific window before travel, commonly 10 days for domestic travel and sometimes shorter for international — scheduling this vet visit with your actual travel date in mind, rather than getting it done too early and having it expire, matters for avoiding a last-minute scramble.
International travel: research destination-specific requirements early
Import requirements vary enormously by country, sometimes including required vaccinations completed well in advance, blood titer testing that itself takes weeks for results, or in some cases mandatory quarantine periods — researching your specific destination's current requirements months rather than weeks before travel avoids discovering an unmeetable timeline too late to adjust.
Airline-specific requirements beyond general travel documentation
Individual airlines often have their own specific carrier requirements, advance notification requirements for bringing a pet aboard, and sometimes breed or size restrictions — confirming your specific airline's current policy directly, rather than assuming general pet travel rules apply uniformly, prevents an unpleasant surprise at check-in.
Keeping physical and digital copies of everything
Bringing physical copies of all required documentation, and keeping digital backups accessible via phone in case physical copies are misplaced, provides redundancy for documentation that's often difficult or impossible to replace quickly if lost during travel.
Rabies vaccination timing for international travel specifically
Many countries require rabies vaccination completed a specific minimum time before travel, sometimes 30 days or more — this is a genuinely common point where owners discover too late that their cat's vaccination, while current, doesn't meet the specific advance-timing window a destination requires.