The credit card mistake that will cost Brits £125m this summer

Elaine Thompson/AP/Press Association Images

When you're on holiday, the last thing you want to be embroiled in is some sort of tricky mathematical gymnastics to work out exactly what you are spending on every single small transaction. It's why it can seem like a huge relief when the retailer offers you the chance to pay in pounds on your credit card - so you know exactly what it's costing you.

However, falling for the 'easy' option could cost you hundreds of pounds on your trip.