I'm keeping an eye out for availability for next year's holiday and want to book 2x F flights using an Amex 2-4-1, and availability will open up while I will be able to earn 12.5 Avios per £1 on my partner's Lloyds TSB Avios Duo Amex.
Will it be an issue if I pay the taxes and charges with this card, and will they ask to see the Lloyds TSB card at the airport? The Lloyds TSB card will be cancelled in a few months, but I have no plans to cancel the BA Amex that gave me the 2-4-1 so presenting that if asked won't be an issue.
EDIT:
I notice that the terms and conditions state...
All British Airways American Express Credit Cards
The Member is responsible for paying any Taxes, Fees & Charges relating to their Companion Voucher booking. All Taxes, Fees & Charges must be paid for using the Member’s British Airways American Express Credit Card.
Does this get enforced in practice? 12.5 Avios per £1 rather than 3 Avios would be rather nice!