Need someone's help or experience on this situation if possible. I don't want to contact the airline just yet, in case they attempt to change booking to one-way which is almost 2x the price.
The issue is not a no-show on the return leg, it's a no-show on the outbound flight.
It's for two passengers with Qantas, return LHR -> SYD. So the two passengers will not show in London, but will expect to use the return leg from Sydney back to London, as they're already in Australia.
I'm worried that a no-show outbound will automatically cancel the return journey.
The issue is not a no-show on the return leg, it's a no-show on the outbound flight.
It's for two passengers with Qantas, return LHR -> SYD. So the two passengers will not show in London, but will expect to use the return leg from Sydney back to London, as they're already in Australia.
I'm worried that a no-show outbound will automatically cancel the return journey.

