Originally Posted by
bakera
Why not just overpay your card. E.g. pay a couple of £k into your account so that your available balance is £card-limit + amount-overpaid
AMEX hates this and usually doesn’t work. So it can cause issues later with AMEX. So I would either call AmEX and increase the credit limit or if you have an another Amex you could move that limit to the BA one.