Dynamic Currency Conversion: Why You Should Always Say No (Part 2 of 3)

The short answer: dynamic currency conversion (DCC) is the offer, at a card terminal, ATM or online checkout, to charge you in your home currency instead of the local one. Decline it and pay in the local currency. With DCC the merchant's payment provider sets the exchange rate, and measured tests show it costs more almost every time: Stiftung Warentest, as reported by the European consumer organisation BEUC, found DCC added 2.6% to 12% at ATMs and 2% to 5% in shops, and a Norwegian bank's study of 1,500 ATM withdrawals found the home-currency option cheaper in only 4 of them.

There is exactly one fee in international payments that you are politely asked to agree to, in writing, on a small screen, while a queue forms behind you.

It is phrased helpfully. "Would you like to pay in GBP instead of EUR?" Yes appears on the right, where your thumb already is. The helpful currency is your own. What could possibly be wrong with that.

This is dynamic currency conversion, and it is the most expensive button in travel.

What DCC actually is

Normally, a foreign purchase is converted by the card network — Visa or Mastercard — at their daily wholesale rate, and your issuer may then add a foreign transaction fee of typically 1–3% (NerdWallet, 2026).

With DCC, the merchant's payment provider does the conversion instead, at a rate they choose. They quote you a figure in your home currency, you approve it, and the transaction reaches your bank already converted.

The pitch is certainty: you see the number in your own money before you agree. That part is true. What is not disclosed with equal prominence is the rate used to produce that number, which is set by the party being paid, not by the network.

DCC is the only case in payments where the person receiving the money also chooses the exchange rate. Nobody designed that arrangement to work out in your favour.

What DCC has cost in measured tests

Most writing about DCC gives a vague "it is more expensive". The tests below put numbers on it. All are reported in BEUC's position paper on dynamic currency conversion of 30 October 2017; they are older than we would like, and nobody has published a larger, newer independent test that we could find.

The pattern is consistent across four countries' tests: DCC is not occasionally worse, it is worse almost every time, and ATMs are where the mark-up is largest.

The arithmetic, on a 100 dinner

Here is what those measured ranges mean on a 100 purchase, against a card that converts at the network rate:

Scale it up and the button stops being trivial. A 500 hotel bill accepted in DCC at the Norwegian study's 7.6% average costs 500 × 0.076 = 38 more than paying in local currency on a no-fee card; at the 12% top of the ATM range it is 60 more. On a 2,000 trip where every payment goes through DCC at 5%, the extra is 100 — for a conversion your card would have done at the network rate.

The bottom row is the one that surprises people. Accepting DCC does not reliably remove your card's foreign transaction fee — the transaction can still be flagged as foreign, because it is. You can end up paying a merchant's mark-up and your issuer's fee on the same coffee.

Where you will meet it

DCC is not rare and it is not a scam operating in the shadows. It is a mainstream product with a sales force, and it appears:

• At card terminals in shops and restaurants, as the screen question.
• At ATMs, phrased as "with conversion" or "without conversion" — the "guaranteed rate" is the DCC one.
• On hotel and car hire bills, sometimes applied by default at check-out.
• In online checkouts on foreign sites, as a pre-ticked currency selector.
• On airline and booking sites, where the currency defaults to your billing country.

The online cases are the ones people miss entirely, because there is no cashier and no queue — just a dropdown that was already set before you arrived.

Why merchants offer it

Not out of malice — out of economics. The payment provider offering DCC shares the mark-up with the merchant. It is a revenue line on a transaction that would otherwise be pure cost. Terminal staff are often trained to present it as a customer service, and in many cases genuinely believe it is one.

This matters for how you decline it: politely, without a lecture. The person at the till did not price the product.

The regulatory position, briefly

In the EU, the rules improved. Regulation (EU) 2019/518 requires providers to disclose currency conversion charges as a percentage mark-up over the latest available euro reference rate published by the European Central Bank, so cross-border euro payments can be compared like for like (EUR-Lex, ECB reference rates).

Disclosure is not prevention. The mark-up must be shown; it may still be accepted. And outside the EU there is often no equivalent requirement at all.

The permanent fix

Declining DCC is free and works every time, but it relies on you being awake at a till after a long flight. Two structural fixes reduce how often it can even come up:

1. Carry a card with no foreign transaction fee so that paying in local currency is genuinely the cheapest path. See our comparison, which also lists the catches.

2. Hold the currency before you travel. If the account already holds euros, there is no conversion at the till to mark up. That is the whole argument for multi-currency accounts — open a Wise account or compare the alternatives on our sister site in what multi-currency accounts really cost.

We work both approaches through the same illustrative amounts in Part 3. And if you are choosing between a travel card and an account in the first place, multi-currency account vs travel credit card is the shorter version.

The one-line summary

Always pay in the local currency of the country you are in. It is the single highest-value habit in international spending, it costs nothing, and it takes one extra second at a terminal.

Next: what actually happens when you run 5,000 through a card and through a multi-currency account.

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Sources

• EU — Regulation (EU) 2019/518 on cross-border payments and currency conversion charges: eur-lex.europa.eu
• European Central Bank — Euro foreign exchange reference rates: ecb.europa.eu
• BEUC — Dynamic Currency Conversion: when paying abroad costs you more than it should, position paper BEUC-X-2017-118, 30 October 2017 (reports the Stiftung Warentest, Norwegian bank and Slovene tests): beuc.eu
• NerdWallet — Best No Foreign Transaction Fee Credit Cards, August 2026: nerdwallet.com
• CNBC Select — Best credit cards with no foreign transaction fees, August 2026: cnbc.com