You can select a seat on British Airways for free starting 24 hours before departure when online check-in opens. However, if you've booked a Basic (hand baggage only) fare, your seat will be assigned automatically at check-in, and you may need to pay to change it.

If you prefer to choose your seat earlier, you can pay to do so at the time of booking or anytime before check-in opens. Passengers traveling in First Class, those with flexible tickets, or British Airways Executive Club members (Silver or Gold) may be eligible for free seat selection earlier, depending on their fare type and membership status.