You pay for a nice dinner in a foreign city. The card terminal asks whether you'd like to pay in your home currency or in the local one. Home currency sounds friendlier. It also usually costs you more.
That prompt is the most common money trap on a trip, and it has a name: dynamic currency conversion. The shop or the terminal provider converts the price at their own rate, which typically includes a markup, and your bank has no say in it. Always choose the local currency.
The usual leaks
| Mistake | What it costs | Better option |
|---|---|---|
| Paying in home currency when asked | A hidden markup on the conversion | Decline, pay in local currency |
| Exchanging cash at the airport | Poor rates, sometimes fees | Withdraw a small amount at an ATM in town |
| Using a card with a foreign transaction fee | Often a few percent on every purchase | Check before leaving; use a card without the fee |
| Withdrawing small amounts repeatedly | A flat fee each time | Fewer, larger withdrawals, within reason |
| Using independent ATMs in tourist areas | High operator fees, poor rates | Use ATMs at a bank branch |
| Carrying only one card | Stranded if it is blocked or lost | Bring a second card, kept separately |
Fees depend heavily on your bank and your card, so read your own terms. Some banks and travel-focused accounts charge nothing on foreign purchases, and others add a few percent. It's worth checking before a trip, not afterwards.
Cash: how much and where
Cash use varies widely. In some countries you'll pay by card or phone for almost everything, including a coffee, and in others markets, small guesthouses and rural buses still want cash. A quick search on the specific country, or a message to your host, tells you what to expect.
I'd arrive with a small amount of local currency, enough for a taxi and a snack, and withdraw more from a bank-branch ATM once I know what's needed. Airport kiosks are convenient and the rates reflect it.
When an ATM offers to do the conversion for you, as the card terminal does, say no. Let your own bank handle it.
Small precautions that help
Tell your bank where you're going if it asks you to; some still block foreign transactions that look odd. Many banks now let you do this in the app, and you can also set limits.
Keep a backup card somewhere else, not in the same wallet as the first. Write down the number to call if a card is lost. A phone that dies on the same day can make that surprisingly hard.
Hotels and car rental firms often place a hold on your card for a deposit. It's released later, but it ties up available funds, which matters if your card has a low limit.
Read your statement when you get home, not just the balance. Look for charges that were converted when you said no, duplicate payments, and deposits that never came back. Disputes are much easier within a few weeks than after several months, and you'll still have the receipts.
Contactless payment by phone is convenient and, in many places, safer than handing over a card. Check that it works abroad before you rely on it.
None of this is complicated. It takes about twenty minutes before a trip, and the savings on a two-week holiday can pay for a good dinner.
