Originally Posted by pauldb

I'm surprised that BA's Conditions of Carriage make so little reference to IDB/downgrades, given they are such common industry practices. The only reference to IDB is:

3c7) We will accept each flight coupon in your ticket for transportation in the class of service on the date and flight for which you have a reservation unless you fail to meet the check-in and boarding requirements in clause 6 or we have to deny you boarding because of overbooking or we exercise our right to refuse to carry you under clause 5d3 or 7.
As I read those conditions, if you present yourself ready and suitable to fly, BA must carry you in the class you booked or exercise their one and only option in the case of overbooking: IDB not downgrading. Of course there's nothing to stop them negotiating with you a downgrade but I can't see how they can compel you.