Short answer
At the airport your onward ticket can be checked twice: by the airline at check-in, bag drop or the gate before you fly, and by the border officer when you land. Have the booking reference, a PDF and a printed copy ready, and make sure the booking is still live at both moments. If an agent refuses it, ask exactly what they need; the fix is usually a different or paid booking, made on the spot.
Two checkpoints, two different questions
| Checkpoint | Who | Their question | What they can do |
|---|---|---|---|
| Check-in, bag drop or gate | Airline staff | Will this passenger be admitted at the destination? | Decline to board you |
| Arrival immigration | Border officer | Does this visitor meet the conditions of entry? | Ask more questions, or refuse entry |
| Connection on a separate ticket | Airline staff | Same as check-in, for the final destination | Decline to board the next flight |
The airline's reason is liability, explained in do airlines check onward tickets. The officer's reason is the entry rules themselves. GOV.UK's advice for British travellers says visitors to Thailand may be asked for evidence of onward or return travel and enough money for the stay, that at Mexican border control you may need a return or onward ticket and proof of accommodation, and that New Zealand border control asks for proof of a return or onward ticket.
What to have on your phone and on paper
- The booking reference and airline name, written somewhere that does not need a signal.
- The itinerary PDF saved offline on your phone.
- A printed copy, for counters that prefer paper or when your battery runs out.
- The airline's Manage booking page bookmarked, to show the live booking if asked.
- Accommodation details and evidence of funds, which officers often ask about in the same breath.
- For a held reservation, the payment deadline, so you know it outlasts both checks.
At the check-in counter
Decide
What the agent says, and what to do
- If the agent asks for proof of onward travelShow the reference and PDF, and offer the reference for them to look up.
- If the agent cannot find the bookingConfirm the airline, the reference and the family name spelling, and show the live booking on the airline's site. See how to verify a flight reservation.
- If the agent says the booking has expiredIt has lapsed at the airline's deadline. You need a new booking or a ticket before you can board.
- If the agent says a paid ticket is requiredA reservation will not change that answer. Buy a refundable ticket or a cheap fare you might use.
- If the agent accepts itKeep it to hand: immigration may ask for the same proof on arrival.
At immigration
Officers may ask a few short questions: how long you are staying, where, and when you leave. Answer plainly and show the booking when asked. If you are entering on a visa that already covers your stay, carry it alongside the booking.
Make sure a held reservation is still live when you land, not just when you check in. On a long journey with connections, that can be many hours later. When to get an onward ticket shows how to time it.
If you are refused at check-in
- 01Ask what would be acceptedA booking with a later deadline, a paid ticket, or a specific route. The answer decides the fix.
- 02Fix it thereCreate a new booking or buy a ticket from your phone. Act quickly, because check-in closes at a fixed time before departure.
- 03Show the new proofGo back to the same counter with the new reference.
- 04Learn for next timeCheck your next trip in advance with Trip Check.
Questions
01Is a screenshot of my booking enough?
It may be, but a screenshot cannot be refreshed. The booking reference, which the agent can look up, and a PDF of the itinerary are more useful.
02Do I need a printed copy?
Not always, but it helps when your phone fails or a counter prefers paper. It costs nothing to carry one.
03Can immigration ask for an onward ticket even if the airline did not?
Yes. The airline and the border officer check separately, and passing one does not rule out the other.
Sources
- 1Thailand travel advice: entry requirements · GOV.UK, Foreign, Commonwealth & Development Office · checked 29 September 2026
- 2Mexico travel advice: entry requirements · GOV.UK, Foreign, Commonwealth & Development Office · checked 29 September 2026
- 3New Zealand travel advice: entry requirements · GOV.UK, Foreign, Commonwealth & Development Office · checked 29 September 2026
Last reviewed 29 September 2026. Rules change: confirm with the airline and the official source before you travel. How we research · Report a correction