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 eight sneaky vacation costs.

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 avoid this artificial price increase.
2. Stealthy fees. The nightly base rate for a fancy resort or self-rental often compares favorably to a standard hotel in the same location. This can be an intentional pricing tactic used to get their property on the initial search results page. Don’t be fooled! These same places often add a daily resort fee or high cleaning cost on to your bill. The extra fees might be worth it to you, but it’s better to understand the full cost of the stay before making your reservation.
3. Bait and switch. In the self-rental marketplace, a property management service may feature a great-looking rental, but when you try to book it, it is not available. They then try to switch you to a less desirable property. Even worse, a single property can be listed on numerous services so that property you think you reserved is actually already rented to someone else!
4. Useless rental car insurance. Rental car companies will try to sell you insurance to cover damages you may cause during the rental period. The auto insurance you already have many times 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.
5. Bloated baggage fees. You probably already know that airlines may charge for checking in a bag, but did 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.
6. 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 ride share options before committing to the hotel rate.
7. 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.
8. 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, bank accounts and cell phones to see if they charge foreign transaction fees. If they do, shop for another card, account or cell phone that doesn’t charge fees.

Everyone expects to pay for their vacation, but with a little planning you can avoid dealing with unpleasant surprises during your vacation!