Going on vacation is a time to get away, relax and enjoy new experiences. But if you don’t pay close attention, extra costs can sneak up on you like tiny money-stealing ninjas. Here are seven sneaky vacation costs to watch out for:

1. Covert airfare increases. Airline pricing algorithms are programmed to store your browsing history to see if you’ve been looking at flights. If you have, they will bump up the price. Before searching, clear your internet history and switch to private (or incognito) mode on your web browser. When you are finally ready to book the flight, do so using a different computer from a new location to be sure that you’re avoiding this artificial price increase.
2. Stealthy resort fees. The nightly base rate for a fancy resort will often compare favorably to a standard hotel in the same location. This is an intentional pricing tactic used by resorts to get their rooms on the initial search results page. Don’t be fooled! These same resorts will add a daily resort fee on the back end of your bill to cover the extra amenities they offer. The extra fee might be worth it to you, but it’s better to understand the full cost of the stay before making your reservation.
3. Useless rental car insurance. Rental car companies will try to sell you insurance to cover damages you may cause during the rental period. Often, the auto insurance you already have will extend to the rental car. In these cases, the extra insurance isn’t necessary. Before renting a car, check with your insurance company to see if a rental will be covered.
4. Bloated baggage fees. You probably already know that airlines may charge for checking a bag, but do you know they will charge extra if a bag is too heavy? Exact weight can vary by airline or location, so check the weight limits before you go and weigh any heavy bags using a bathroom scale.
5. Crafty parking costs. Downtown hotels in big cities charge as high as $75 per night for parking! Research alternative parking options near your hotel or compare the cost of using rideshare options before committing to the hotel rate.
6. Sly extra driver charges. Rental car companies will charge an extra daily fee to have a second driver listed on the rental. If possible, commit to one person to handle all the driving on your vacation.
7. Tricky foreign transaction fees. Traveling abroad and paying an extra fee for every purchase will add up in a hurry. Before you go, check your credit cards and bank accounts to see if they charge foreign transaction fees. If they do, shopping for another card or account that doesn’t charge fees might make sense.

Some vacation fees can’t be avoided, but many of them can if you know where to look. Implement a plan to navigate the fees in the planning stages of your trip to avoid dealing with them during your vacation.