The money-saving expert says many travellers unknowingly make the wrong choice at cash machines and checkouts – one that hands control of the exchange rate to foreign banks or retailers.
It’s a quick tap most people don’t think twice about, but over the course of a trip, it can quietly add up.
According to Lewis, the fix is straightforward – and getting it right could make a noticeable difference to how much you spend while away.
The quick tap that can cost you
When paying or withdrawing cash abroad, you’re often asked whether you want to be charged in pounds or the local currency.
“When you go abroad and you pay on plastic and the overseas cash machine or shop asks you, do you want to pay in pounds or euros, what do you do?” he said.
“The correct answer is you should always pay in euros, or whatever the local currency is, because that means it’s your plastic that’s doing the exchange rate conversion, not the overseas shop or ATM.”
He added that even standard UK cards often still work out better overall than letting foreign machines set the rate themselves.
“Even a bog-standard UK credit or debit card… is beating most overseas ATMs or shops’ exchange rates,” he said, based on his testing.
His advice is simple: stick with the local currency every time, whether that is euros, dollars, or even dong when travelling further afield.
It might seem easier to pick pounds, but that’s where people go wrong.
Lewis says the rule is simple: always choose the local currency – whether that’s euros, dollars, or anything else.
By doing this, your own bank or card provider handles the conversion, which is typically more competitive than the rates offered by foreign ATMs or retailers.
Even standard UK debit or credit cards can outperform the exchange rates set by overseas machines, meaning that one small choice could save you money every time you use your card.
Why dynamic currency conversion adds up
The trap is known as “dynamic currency conversion.” It’s designed to feel convenient, showing you exactly what you’ll pay in pounds — but that clarity often comes at a cost.
The exchange rate used is usually less favourable, and extra fees can be baked in without being obvious.
While a single transaction might not seem like a big deal, repeated spending – meals, transport, shopping – can quickly add up over a holiday.
A spokesperson for travel experts Ski Vertigo added: “This is a mistake many travellers make without realising. The option to pay in pounds can seem like the easier or more familiar choice, but it often comes with a less favourable exchange rate and extra charges built in.
“Those small decisions each time you make a withdrawal may seem minor, but they can quietly add up across several days of spending.”
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Travel experts also warn that many people don’t check their card’s foreign usage fees before leaving the UK, which can further increase costs.
If you’re travelling abroad, the advice is straightforward: always pay in the local currency.
It might feel counterintuitive at first, but that one choice can help you avoid hidden charges and get a better deal throughout your trip.
