Ambassador, British Airways Executive Club, easyJet and Ryanair
Join Date: Sep 2011
Location: UK/Las Vegas
Programs: BA Gold (GGL/CCR)
Posts: 15,930
Presumably PayPal would transact in GBP with your debit card? It sounds like your debit card is one of those that does not permit foreign currency transactions. If so this is outside the control of BA (well to the degree they only permit transactions in the currency of the country of the originating flight).