When you buy a one way international flight ticket and check in at the departure airport, the airline will usually want to see an onward ticket. Why?
Why You Need Onward Tickets And Who Asks To See Them
If, for any reason, immigrations deny you entry at your destination, the airline would have to pay for your flight back to your original destination. Since it costs them money, they want proof of onward travel from anyone who checks in with one way tickets.
However, some airlines don’t ask to see onward tickets. If you go check in at an airport with a one way ticket, you’re taking a chance and betting that they would not ask. But if they asked you to show an onward ticket when you didn’t have one, they would not let you board the flight.
The reason I had an onward ticket when I checked in at the airport on July 10 was because the consulate required it for issuing my visa. But neither the airline asked to see it, nor did immigration at the destination airport. Perhaps I got lucky this time. Other expats have related mixed experiences — some didn’t bother getting an onward ticket and never had a problem. Other expats were forced to buy an onward ticket on the spot, running across the airport to buy that ticket, running back to the check-in desk, and rushing to the gate barely making the flight in the nick of time.
Gaming The System
I’ve heard some expats say they’ve had success forging airline tickets and using them as fake onwards. Either they change the date on an old ticket, or they go through the booking process for a new ticket but stop short of paying, copy the ticket into Word, change the wording to “confirmed”, and print it out.
I don’t recommend this. It’s not a good idea and you’re asking to get caught, even if you’ve gotten away with it before.
You Have Options
So I would advise to forget about this monkey business, especially on costly international long haulers or with airlines that have a reputation of being strict. Other airlines may be lax about this, but it’s probably only a matter of time before they tighten things up, too.
What you could do is book the cheapest refundable ticket you can find and cancel it once you pass immigrations or within 24 hours. Or you could actually use the ticket to fly to your next destination that you’ve always wanted to visit. You could even use flyonward.com if you’re okay with dropping $10 and not actually using those tickets. You could also wait to buy a ticket at the last minute after the check-in agent tells you need one, but I imagine that would be a very stressful experience. I personally hate running around in the airport like a chicken with its head cut off.