Then it is married.Misread that. Doesn't show up as LHR-SIN.
Here’s an example of married segments in action. One member is currently attempting to book two connecting flights on Cathay Pacific using points. They can find award availability if they search for the flights individually, but due to married segment logic they appear as unavailable if booked together. The only way to get around this is to book the flights separately or to add a break of more than 24 hours between flights.
What are Married Segments?
Image: Adobe Stock. If you've ever booked a flight, chances are you've come across the issue of "married segments". But what are they, and how do they

