I have a return leg of a trip for 4 adults and 1 lap infant booked using Avios and 2 x Amex Companion Vouchers.

One of the adults will not be travelling however I am unsure if I should undertake an OCI for him. The benefit would be that the seat he is allocated could be used by the infant.

I am of course under no illusion that the companion voucher nor the Avios points will be returned for the non-flown sector however if possible I would like to recover the tax (less admin fees etc) which has been paid. Any advice on how to do this and is it better to do this if the non flying passenger is checked in and “misses” the flight or if they are not checked in from the off.

Many thanks.