When a card terminal or ATM abroad asks whether you want to be charged in the local currency or your own, pick the local currency. Paying in the local currency when traveling is almost always cheaper, because the home-currency option runs your purchase through a service called dynamic currency conversion (DCC) that typically buries a 3% to 7% markup inside the exchange rate. Even after your card issuer adds its own foreign transaction fee later, the total cost of paying in local currency is nearly always lower than accepting the converted price on the screen.
Why the Home-Currency Option Costs More
The moment you insert or tap your card at a foreign terminal, the system reads your card’s issuing country and flags it as foreign. A third-party processor then offers to convert the purchase into your home currency on the spot and shows you a familiar-looking total before you confirm. The merchant’s terminal is essentially outsourcing the currency math to that processor rather than letting your own bank handle it later.
The rate the processor shows you is not the market rate. It is the wholesale interbank rate plus a markup that commonly runs 3% to 7% of the transaction value. Mastercard’s own merchant guide shows real-world markup examples of 3%, 3.5%, and 4.75%.1Mastercard. Dynamic Currency Conversion Performance Guide – Merchant Version The markup does not appear as a separate line item; it is folded into the exchange rate itself, which is why it feels invisible unless you compare the offered rate against the actual market rate on your phone.
Here is what that looks like in practice. Suppose you are buying something priced at €100 and the real market rate is $1.10 per euro. Your total should be around $110. But if the DCC processor applies a 5% markup, the effective rate becomes roughly $1.155 per euro, and you pay about $115.50. That extra $5.50 goes to the processor and the merchant.
Decline the conversion and pay in the local currency, and your card network (Visa, Mastercard, and so on) converts the charge later during settlement using a rate very close to the interbank midpoint, which is simply the average of the buy and sell prices banks trade currencies at on global markets.
What Your Card Charges Either Way
Whichever currency you pick at the terminal, your card issuer and payment network may still charge fees for processing an international transaction. These typically total 1% to 3% of the purchase amount and come from two layered sources: a cross-border assessment from the card network for routing the transaction, and an international service fee your issuing bank may add on top. Both usually appear on your statement as a single “foreign transaction fee.”
These costs apply whether you pay in local currency or in home currency. That is the whole point of the comparison. Choose home currency and you pay both the DCC markup and your issuer’s foreign transaction fee. Choose local currency and you pay only your issuer’s fee.
Your Right to Decline DCC
Both major networks require merchants to give you the choice. Mastercard’s standards state that no currency conversion method may be set as the default, that the cardholder must not be steered toward DCC, and that both currency options must be presented equally in manner and prominence.1Mastercard. Dynamic Currency Conversion Performance Guide – Merchant Version If you do not explicitly choose your billing currency, the transaction must be processed in the local currency. Visa’s policy is similar: merchants and ATMs must give you a choice and cannot decide on your behalf or use design tricks like different font sizes to influence you.2Visa. Dynamic Currency Conversion Explained
Enforcement is inconsistent. Some merchants pre-select the home-currency option on the screen. Some staff tap through the prompt before handing you the terminal. Restaurant servers processing your card out of sight may pick home currency without asking. When that happens, you have recourse. Both Visa and Mastercard maintain specific dispute reason codes for incorrect currency transactions where DCC was applied without the cardholder’s agreement. To defend against a dispute, the merchant must produce proof that you actively chose DCC. If they cannot, the chargeback stands. If you spot the conversion only after the fact on your statement, contact your card issuer and request a dispute under the incorrect currency code.
Check the Receipt Before You Leave
When you do accept DCC, your receipt should contain enough detail to verify the cost. Under Mastercard’s rules, a DCC receipt must include the total in the local currency, the total in your converted currency, the currency codes for both, and the exchange rate used. Any additional fees, including the markup percentage, must also be disclosed.1Mastercard. Dynamic Currency Conversion Performance Guide – Merchant Version Missing details strengthen your position if you dispute the charge later. Compare the rate on the receipt against the current market rate on your phone. If the gap is bigger than you expected, ask the merchant to void the transaction and reprocess it in local currency.
The Same Trap at Foreign ATMs
ATMs abroad run the same offer. After you enter your PIN and withdrawal amount, the machine may offer to convert the withdrawal into your home currency “for your convenience.” The markup works identically. Decline and withdraw in the local currency.
Withdrawals come with a few extra practical points. Most U.S. bank accounts set daily ATM limits, commonly between $300 and $1,500, though the exact figure depends on your bank and account type. If you need more than your limit allows, contact your bank before traveling to request a temporary increase. Foreign ATM operators also frequently charge a flat fee per withdrawal on top of anything your bank charges, so fewer, larger withdrawals tend to be cheaper than frequent small ones.
Currency Choices at Online Checkouts
International e-commerce sites often show a dropdown or toggle letting you view prices in your home currency. This works like DCC at a physical terminal: the site’s payment gateway converts the price using its own marked-up rate. Selecting the merchant’s local currency and letting your card issuer handle the conversion almost always costs less.
One boundary is worth knowing. Some larger online retailers use multi-currency pricing, where they set fixed prices in several currencies as part of their catalog. In that case you are not choosing a conversion; you are choosing which of the retailer’s set prices to pay. Multi-currency pricing uses rates the merchant updates periodically and does not necessarily carry the same point-of-sale markup DCC does. If an online store shows your currency throughout the browsing experience rather than only at checkout, it is likely using multi-currency pricing, and the cost difference compared to paying in the store’s base currency may be small or negligible.
Cards That Waive Foreign Transaction Fees
The structural fix for international card costs is carrying a card that waives the foreign transaction fee entirely. Many travel-focused credit cards charge no foreign transaction fee at all, with annual fees ranging from $0 to several hundred dollars depending on the rewards structure. If you spend a few thousand dollars abroad each year, a 1% to 3% foreign transaction fee adds up to more than many annual fees.
A handful of checking accounts do the same on the debit side, and some reimburse ATM fees charged by foreign bank machines, which matters when you need cash. A card with no foreign transaction fee, combined with always choosing local currency at the terminal, gets you as close as possible to the real market exchange rate.
A Note for Business Travelers and Large Conversions
If you travel for business, all amounts on a U.S. tax return must be expressed in U.S. dollars, and expenses paid in foreign currency are translated using the exchange rate on the date you paid.3Internal Revenue Service. Foreign Currency and Currency Exchange Rates
For personal travelers, the picture is simpler. If you buy foreign currency, spend some, and convert the rest back at a different rate, any gain from the rate change is technically taxable, but federal law provides a practical exception: you do not need to report a currency gain on a personal transaction unless the gain exceeds $200.4Office of the Law Revision Counsel. 26 U.S. Code 988 – Treatment of Certain Foreign Currency Transactions Business travel expenses under Section 162(a)(2) of the tax code get the same personal-transaction treatment, so the $200 threshold applies to those as well. Most casual travelers will never hit it, but anyone converting large sums back after a trip should know it is there.