Foreign Transaction Fee Calculator: Your Real Trip Cost

The fee on a card payment abroad is almost never a single number. It is a currency markup, sometimes a flat charge per purchase, a separate set of rules for cash, a monthly plan fee if you pay for one, and the cut the shop's own terminal takes if you let it bill you in pounds. This calculator adds all five up for one trip and puts your cards side by side. The last of them is the one people miss: accepting "pay in GBP" at the terminal takes a slice before your card is involved at all, so it costs the same whichever card you are holding.

Where the money actually goes

Five charges can land on the same holiday, and they are set by different people.

The currency markup is your card provider's own margin on top of the wholesale rate. It applies to card payments and to cash, and it is the one number most comparisons stop at. A flat fee per transaction is rarer but brutal on small purchases: a fixed charge on a coffee is a far bigger percentage than the same charge on a hotel bill. Cash machine fees follow separate rules, often a fee-free allowance and then a percentage or a flat amount per withdrawal, which is why the calculator asks how many withdrawals rather than just the total. A plan fee belongs in the sum if you are paying for a subscription account mainly to get better travel terms, because for a single trip it can swamp the markup it saves. And the terminal's own conversion, dynamic currency conversion, is charged by the shop's payment provider rather than your bank.

That last one is the reason the calculator applies it to every card equally. If you press the button that bills you in pounds, the exchange rate is chosen before the transaction reaches your card, so the fee-free travel card in your hand no longer helps. Anything billed to you in pounds is a sterling payment as far as your provider is concerned, so its own markup and its flat non-sterling fee both fall away on that share of your spending, and the calculator takes them off. Always choose the local currency and let your own provider convert.

Finding your card's real numbers

Do not rely on the marketing page. Every UK card publishes a fees document, usually called a fee information document or a tariff of charges, and it lists the non-sterling transaction fee, the non-sterling cash fee and any fixed amounts per withdrawal. App accounts put the same detail in the help section, normally under fair usage limits for cash abroad, and those limits often reset monthly rather than per trip, so if your holiday straddles a month end you may get two allowances. Enter what applies to your trip in the fee-free cash box.

Two other things change the answer and are worth checking before you travel. Some accounts widen their spread at weekends, when the underlying market is closed, so if most of your spending happens on a Saturday, nudge the markup up. And a credit card can add a cash advance fee plus daily interest from the moment you withdraw, which sits on top of everything in this tool. For cash, a debit card or a prepaid travel account is nearly always the cheaper instrument.

What usually wins

For most trips the pattern that comes out of this calculator is the same. Card spending is where the markup does the damage, because it is the biggest number, so a card with no markup on purchases wins even if its cash terms are mediocre. Cash is where flat fees do the damage, so take out fewer, larger amounts and carry them. Paying a monthly plan fee only pays for itself on longer trips or high spending, and the calculator tells you exactly where that line sits: raise the plan fee until the ranking flips.

Carrying two cards from different providers is cheap insurance and costs you nothing extra on this maths, because you only pay fees on what each one is used for. Keep the low markup card for spending, keep a second card in a different place for the moment the first is blocked, and compare both here before you pack.