I’m a Revolut user from Spain. Paying with Revolut at POS terminals can be a bit tricky as in Spain, the people are used to handing over the card to the merchant. As 99% of the terminals accept NFC payments, merchants tend to put your card on the POS terminal that doesn’t ask you for a PIN of the payment is below 20 EUR. I’d say about 30% of the POS terminals ask you if you want to pay in GBP.
The message on the terminal is in English and shows 2 options: GREEN BUTTON: Pay in GBP. RED BUTTON: Pay in EUR.
Merchants normally don’t understand English and tend to press the GREEN button.
It happened to me twice at McDonalds’ Drive Thru that I would hand out my card and seconds later they already charged me in GBP (with a ridicolous markup).
For this reason, I have disabled NFC payments, and when I pay with, I keep the terminal in my hand after typing the PIN, till I’m sure the payment has gone through in Euros.
Secondly, the ATMs withdrawals: Most banks don’t charge anything for ATM withdrawals with foreign cards. Just skip BBVA and Sabadell. The largest bank, Caixabank, has free withdrawals. (Oh, and btw, I know from experience that BBVA charges the same for any foreign card. Its not like they do thisonly to Revolut)