Some airlines, notably the low cost carriers, sell tickets where every fare is one way. So, you could buy a one way ticket from A to B, and the fare from B to A is also one way. Roundtrip purchase is not required. So, if you fail to use the originating flights (the airline will cancel all remaining space unless you notify them in advance) you can still use the return. Therefore, the solution is to verify that the fares are one way and roundtrip purchase is NOT required whenever you purchase a roundtrip ticket.
|