Originally Posted by
remymartin
Imagine you would live in an outstation (e.g. TYO). You could only use that voucher to go to HEL.
I think that it is usually better to use the FFP of the airline you use the most. If you live in Tokyo, this probably means JL. AY would only make sense if you make lots of trips to Europe as you could then use the vouchers on the NRT-HEL flights and, if applicable, on any connecting AY short-haul flights.