Unexpected charges and fees can put a serious damper on a vacation abroad. When it comes to using your debit card overseas, understanding the fees involved with ATM withdrawals and debit card purchases can help you plan appropriately and minimize your costs.

Just like with credit cards, you can incur charges every time you take out local currency from an ATM or choose to pay with a debit card in a restaurant or a store.

>> MORE: ATM and debit foreign transaction fees listed by bank

There are two types of debit card fees you may face overseas:

• Foreign transaction fee: This fee, also called a currency conversion fee, usually ranges from 1% to 3% of the debit card purchase amount.

• International ATM fee: At the ATM, banks or credit unions typically charge a flat fee — often $1 to $5 — for using an ATM network in another country, plus a percentage of the amount you withdraw. The fee may or may not be the same as your institution’s out-of-network ATM fee.

Keep in mind that when you use an ATM in another country, the owner of that ATM might have its own fee in addition to what your bank or credit union charges. Usually there’ll be a notice to alert you to the charge so you’ll have an opportunity to cancel the transaction.

» MORE: NerdWallet’s best no foreign transaction fee credit cards

How to keep foreign transaction fees low

Credit unions often have lower international transaction fees than banks. They may only pass on to members the currency conversion charge from Visa and MasterCard, around 1%, with no additional fee added. Banks, in contrast, may tack on an extra 1% to 2% to the card company’s cost.

On the other hand, some large banks have branches and ATMs in foreign countries, where travelers may be eligible for free services. Others have partnerships with foreign banks with similar benefits. Before you travel, check if your bank has an arrangement of that type at your destination.

For customers with premium checking accounts, financial institutions may waive certain fees, including international fees. Check the terms of your particular account, or speak to a representative, to find out if you get perks like that.

If a merchant offers to convert your purchase to U.S. dollars rather than using the local currency, decline this more expensive option. This service, called dynamic currency conversion, sounds like a convenience, but you’ll often end up with a worse exchange rate. When taking out cash from the ATM, always choose the local currency rather than U.S. dollars.

Before you depart, it’s a good idea to inform your bank or credit union of your travel dates so that when you ring up purchases in Paris or Tokyo, it won’t suspect identity fraud and freeze you out of your account. Double check fees with your institution to make sure you understand the most economical way to use your debit card on your trip. If the foreign transaction fees seem too high, especially if you’re going to travel frequently, consider opening another account at a more travel-friendly bank.