If you are off to Spain this Summer, you need to be aware that the "Charge your Card in £££ not €€€" (at a carp rate of exchange) scam is alive and well - the damage is around 5% of the transaction total if you fall for it.
I reckon well over 50% of merchants tried this on me during my recent holiday - and it has got *much* harder to spot what they are up to.
It used to be that the card reader screen asked a very obvious question and you simply pressed the "Pay in €€" button - but now the *merchant* is the only one who sees the 'option' and is supposed to ask you which currency you prefer to pay in - you then get a message along the lines of "Accept Amount" and if you push 'Yes' you are deemed to have accepted the conversion to £££. Not all merchants are exactly squeaky honest about this process.
I'm pretty savvy, but this is makes hard work of a simple transaction - I luckily spotted the trick at my first big transaction (which I was checking very carefully) - I then insisted on the bill being voided/refunded and rebilled in €€ - which seriously annoyed the haughty hotel clerk.
After a couple of near misses, I eventually got caught out at a filling station - not a word was exchanged, I was just routinely and efficiently ripped off for a handful of €€€ - and didn't spot it until I was going through my receipts at home tonight and checking them against my online banking.
It's a nasty scam - which makes money for the Spanish Bank and the Retail Merchant - try not to fall for it.
[ Portugal seemed a bit straighter - still the old system where you have to accept the conversion on the card reader - but it's still all too easy to cock it up after a few beers and a good meal ]
But this time I had several hotel bills to pay and (a lot) of petrol to buy - cards were the only answer, but the need to be alert to the fiddles got very wearing.