A passport that has not expired can still keep you off a plane. Many countries want it to remain valid for months after you arrive, and airlines check this at the counter because they can be responsible for flying someone who is refused entry. It takes a few minutes to check before you book, and that can save the whole trip.
What the six-month rule actually means
The US State Department says many countries require at least six months of validity remaining on your passport to enter, and more may be needed where a visa is involved. It is not one worldwide law. Each country sets its own rule, and they differ:
- Some require six months beyond your departure from the country. Singapore is an example.
- Some require less. Germany asks for three months beyond your departure but recommends six.
- Some measure from your arrival date rather than your departure date, so read the wording.
Airlines can apply their own check as well, so a simple habit keeps things easy: if your passport has under six months left on your return date, renew it before you book.
The checklist before you pay
- Find your expiry date. Compare it to your return date, not your departure date.
- Check the country page. The State Department's travel.state.gov site has an entry-requirements section for every country.
- Count your blank pages. The State Department advises having at least two, and some countries can deny entry without enough room.
- Check visas. Look up whether you need a visa, an electronic authorization, or nothing for your length of stay.
- Check every stop. A connection can bring its own rules, as explained below.
- Match your name. The name on the ticket must match the passport. Fix any mismatch before you book, because airlines generally do not allow name changes.
Connections can catch you out
Your destination might not be the only country that matters. Many travelers forget about the stop in between:
- Airside transit. If you stay airside, you often need no visa, but this depends on the country, your passport and how your tickets are booked.
- Separate tickets. If you must collect bags and check in again, you may need to enter that country, and then its entry rules apply to you.
- Overnight layovers. Leaving the airport for a hotel usually counts as entering the country.
Our multi-city guide and layover guide can help you plan these stops.
Europe has changed its border checks
Traveling to the Schengen area means meeting its passport rules, as well as its new digital border system. Our guide to the Entry/Exit System and ETIAS covers what US travelers can expect on arrival.
Other documents worth checking
- Proof of onward travel. Some countries and airlines can ask to see a ticket showing how you will leave.
- Children. Every child needs their own passport, and passports for children under 16 last for only five years. If one parent travels alone with a child, carry a signed consent letter.
- Health requirements. Some destinations ask for proof of certain vaccinations, so look at the country page and the CDC traveler pages early.
How long renewal takes
As of November 2026, the State Department lists routine processing at four to six weeks, with expedited service at two to three weeks. Those figures do not include mailing time, which can add up to two weeks each way, so check its processing page for current times before you commit to dates. Eligible adults can also renew online, and urgent travel has its own appointment process.
A sensible order: confirm your passport, check the country rules, then pick your booking window and compare flights. If you need a starting point, see Miami to Madrid or Washington to London.
