We are planning to take the kids away for Christmas next year using 2 x 241s.
We have (or will have very soon) 2 vouchers on mr Flyer's account which we can use for 4 of us - no problem as long as I can find the flights.

However in the summer OH and I are planning an eclipse trip to the US and will need a 241 for that. By the time we need to book the summer trip my son will have generated a 241. I know we can't use this because the voucher earner has to be travelling.

Is it possible though to ring BA and change one of the vouchers that we redeemed for the Christmas trip from OH's to son's? Then we would have an OH voucher to use for the summer.