The passport rules that stop you at check-in

The six-month rule

Many countries require your passport to remain valid for six months beyond the date you arrive. Some use three months. A few only require validity for the length of the stay.

The consequence is the part people miss: a passport that comfortably outlasts your trip can still be refused. Flying in October on a passport expiring in February satisfies “valid for my holiday” and fails a six-month rule. And you will usually be stopped by the airline at check-in, not by immigration on arrival — the carrier is fined for bringing an inadmissible passenger, so it enforces the rule strictly and at the earliest possible moment.

Renewal takes weeks in normal times and much longer in busy periods. The practical rule is to treat any passport with under nine months left as needing action before you book anything, not before you fly.

Blank pages, and the other physical checks

• Blank pages. Commonly one or two entirely blank, and some countries specify pages headed “visas” rather than any blank page. Frequent travellers hit this before they hit an expiry date.
• Damage. A water-damaged, torn or unreadable passport can be treated as invalid entirely. A passport through a washing machine is a new passport, not a risk worth taking.
• The name matching the ticket. It has to match the passport, not your everyday name. A married name on a booking and a maiden name in the passport is a real and common refusal.

Visa, entry authorisation, visa on arrival

• A visa is applied for in advance, often with an appointment, documents and weeks of processing.
• An electronic travel authorisation — the US ESTA, Canada’s eTA, the UK’s ETA, the EU’s ETIAS — is not a visa, but it is mandatory, it is bought online, and you will not be allowed to board without it. It is the one people forget precisely because it does not feel like a visa. Approval is usually minutes, occasionally days, so leaving it to the airport is a genuinely bad bet.
• A visa on arrival is obtained at the border. It still often requires a specific fee in cash, a photograph, and proof of onward travel.

Buy these from the official government site. The search results above it are resellers charging a substantial markup for the same form, and some are worse than that.

Which passport you use changes the answer

If you hold two, the requirements are per passport, and so are the awkward interactions: some countries refuse entry on evidence of travel to another, and some require their own nationals to enter on their own passport. Airlines check the passport you present at the desk, so the choice has to be made before check-in and stay consistent.

Everyone travelling needs their own answer. It is easy to check your own passport carefully and never check the people going with you — and children’s passports are issued for shorter terms, so they expire sooner than anyone expects.

The conditions checked at the desk

• Onward or return ticket. Widely required as proof you intend to leave, and enforced by airlines on one-way bookings.
• Where you are staying. An address is commonly asked for on the arrival form.
• Vaccination certificates. Still required for some destinations, notably yellow fever in parts of Africa and South America.
• Transit. A layover can require its own transit visa even when you never leave the airport — and changing terminals or collecting a bag usually counts as entering the country.

Where TripTov fits

TripTov holds each traveller’s passports — yours and your companions’ — and checks them against the countries a trip actually touches, including ports of call and layovers. It warns on the six-month rule by name, so the message says which person’s passport is short rather than that “a passport” is, and it reminds you far enough ahead that renewing is still possible. Try it, or read the cancellation deadlines worth putting in your calendar.