Originally Posted by
happyintheair
There used to be surcharges for paying with personal cards on BA,but these are long gone.
My guess is that your Amex has been (wrongly) flagged as a corporate one hence the surcharge.
You could wait and it might get corrected, or raise a dispute with Amex ,that would cut down on the waiting time.
Current rules for corporate card costs here
https://ndc.ba.com/faq/commercial/payments?bk=Y3
Raising a dispute with Amex could cause more problems. It’s a small amount of money, so I would wait for BA customer services to refund it after raising the issue via a complaint.