Visa and Mastercard exchange rates: 8 key terms

On a payment in foreign currency, your bank does not set the starting rate. The network printed on the card, Visa or Mastercard, publishes a reference rate every day, and everything else stacks on top of it. Here are the eight terms that really decide the amount debited from your account.

Visa or Mastercard exchange rate: which one applies?

The one from the network printed on your card. A Visa Debit card converts at the Visa rate of the day, a Mastercard card at the Mastercard rate. Both track the market closely, and the gap between them plays out in the third decimal.

Your bank comes in afterwards. It lays its own fee on top of that reference rate, and that line is what widens the price gap between two Belgian cards. Visa offers a public exchange rate calculator where you can replay a past transaction, date by date; Mastercard offers the equivalent. I got into the habit of going back there whenever a debit looked too heavy. Two times out of three, the gap came from my bank and not from the network.

What is the interbank rate?

It is the price at which banks exchange currencies between themselves. Google, XE and Wise display that rate.

No card gives it to you exactly.

The reference rate published every business day by the European Central Bank is its official version, fixed in the middle of the afternoon. It serves as the yardstick in European law: since 2019, any currency conversion markup on a card transaction must be expressed as a percentage above that rate. Without it, comparing two offers is guesswork.

Which 8 terms decide the price?

None of them is complicated. Taken together, they explain the entire gap between the rate you see on Google and the amount debited.

Pricing checked on 30 August 2026 against the public terms of the issuers named. Your own card's markup sits in your pricing terms, under 'exchange fee' or 'fee on transactions in foreign currency'.

Exchange markup and weekend surcharge: how much do they cost?

The exchange markup is the item you can bring down to zero. On a standard Belgian credit card it sits around 1.5% to 2%; on entry plans at Revolut, N26 or Wise it drops to 0% within a monthly allowance.

The weekend surcharge is sneakier, because it never appears on the merchant's receipt. From Friday evening to Sunday evening, currency markets are closed: the institution doing the conversion takes a risk on Monday morning's rate, and it charges you for that. On free plans, that extra sits around 1%, checked on 30 August 2026 on Revolut's public pricing page. Wise is the exception and applies the real rate continuously.

One Sunday evening in Lisbon, I converted €300 in one go rather than payment by payment. Bad instinct: the surcharge applied to the whole amount. By Monday morning it was gone.

Pay in euros or in the local currency abroad?

Local currency, always. When the restaurant terminal or the ATM screen offers to settle 'in EUR' at a displayed rate, that is dynamic currency conversion, and it is almost always more expensive.

The mechanism is easy to spot once you know it. The merchant, or the ATM owner, steps into the card network's place, sets the rate shown on the screen itself, pockets the difference between that rate and the network's, and makes you lose the Visa or Mastercard rate your card entitled you to. In London, on a £100 bill, accepting a conversion at 5% adds roughly £5 to what the card alone would have charged. For two seconds saved on a screen.

Why does dynamic currency conversion cost so much?

Because whoever offers it earns from it directly. The displayed rate is capped by nothing: it is free, and the margin is shared between the merchant and its terminal provider. Nothing forces anyone to calibrate it on the market. Airport concourse and tourist-street machines live off it, and the default setting there always pushes towards the euro. A friend got caught in Prague on a 5,000 CZK withdrawal, on a screen that framed paying in euros as the reassuring choice.

European law does not ban the practice, it makes it visible. Since Regulation (EU) 2019/518, the margin must be shown to you before you confirm, expressed as a percentage above the ECB reference rate. Read that line. It tells you at a glance whether the screen is offering 4% or 11%, and the answer stays the same either way. A display that hides that margin is a breach, reportable to the FPS Economy, the Belgian federal consumer and market authority.

Outside the euro area, what extra fees apply in Belgium?

Two, on top of the exchange. The first belongs to your card: most Belgian cards charge a fee on payments in foreign currency and a second one, often a flat amount, on withdrawals outside the euro area. The second goes to the foreign ATM, taken on the spot and independent of your bank.

One Belgian point stays widely misunderstood. The bank card issued here has been co-badged since Maestro was progressively withdrawn: a Bancontact function, the Belgian debit card payment scheme, for use in Belgium, and a Visa Debit or Mastercard Debit function for abroad. Beyond our borders, the second one does the work, so your bank's international pricing applies and never the Bancontact tariff. Neobanks only have the international function: their problem is the mirror image of yours, and it shows up in Belgium, as I explain in our article on Bancontact and neobanks. Wikifin, run by the FSMA, the Belgian financial markets regulator, is a useful place to re-read those lines before you travel.

Which habits to adopt before paying abroad?

Five moves recover most of the gap:

• Decline conversion into euros, at the merchant terminal as well as at the ATM screen, without exception.
• Avoid independent machines in airport concourses and tourist areas, where dynamic currency conversion is the default setting.
• Withdraw less often and more at a time as soon as a flat fee applies to each withdrawal.
• Convert on weekdays if your plan adds a surcharge at the weekend.
• Re-read your pricing terms before leaving, the 'transaction in foreign currency' line, and compare it to the reference rate of the day.

Our comparator puts neobank exchange pricing side by side, and the article on the best neobank for travel covers each one's free allowances.

In short

The Visa or Mastercard rate is not the problem: it tracks the market. The cost comes from the stack on top of it, the issuer's markup, the weekend surcharge, the ATM fee, and above all dynamic currency conversion as soon as you agree to pay in euros. The rule fits in three words: always local currency. The rest is settled once and for all, by picking a card with no exchange fee and re-reading its pricing terms before you pack.

This article provides pricing information and is neither legal advice nor investment advice.

Sources: European Central Bank (euro foreign exchange reference rates), Regulation (EU) 2019/518 on currency conversion charges, FPS Economy (payment fee transparency), Wikifin (FSMA), Test-Achats (replacement of Maestro by Visa Debit and Mastercard Debit), Febelfin (Bancontact share of card payments), public Visa and Mastercard converters, Revolut, N26 and Wise pricing terms checked on 30 August 2026.