Reply To: Booking a 241 Companion Voucher flight at 355 days

[NorthernLass]

If you book the return leg online you can get back the extra avios but NOT the taxes. If you call and ask BA to add the return leg, they should recalculate the taxes so you don’t end up paying over the odds, however obviously you are dependent on getting through on the phone before the seats go. The surcharges each way are different so you’d have to check the exact amount they quote you. There are a couple of HFP articles about the best way of doing this.