Are you going on vacation this summer? Will you be renting a car? If yes, pay attention, because car rentals are subject to some truly nasty hidden fees that can leave you feeling taken advantage of by the rental company. A car that’s advertised for as little as $10 a day could end up costing you $100 per day once all the extra fees and costs are factored in, and the rental companies almost never discuss the fees hidden in their contracts. If you’re not careful, these additional costs can leave you penniless, so here are the most common hidden car rental fees that you should be aware of, and what you can do to avoid some of the more heinous ones.

10. Airport Surcharge

Talk about a gut punch. If you’re renting a car at an airport in the near future, then you should be aware that most car rental companies will charge you what’s called an “airport surcharge,” based on the location where you get the rental. What exactly is the airport surcharge for? Allegedly, t’s to cover the money the car rental company pays to rent counter space at the airport, and it can be an additional 7-10% on top of your final bill. Brutal, we know. Sadly, the only way to avoid this charge is to not rent a car at an airport. Easier said then done, right? In the end you will need to weigh the cost of the airport surcharge against the inconvenience of having to rent a car away from the airport that you are already flying in and out of.

9. Drop-Off Charges

Another hidden fee related to the location of the car rental company, drop-off charges typically apply if you return a rental car at a location that’s different from where you first rented the vehicle. If you do this, an extra fee of 15% to 20% may be charged if the car you rented is returned to a different location, with how much you’re charged based on the distance between the pick-up and drop-off spots. Basically, the rental car company is charging you for the inconvenience of having to get the car you rented back to its original location. You need to keep this in mind because, in some companies, there is no charge specified by the rental agreement if you return a vehicle in a different place from where you picked it up, but that doesn’t mean it doesn’t exist. In some cases, rather than a flat amount, the daily rate that you are charged to rent the car will end up being higher than if you rented and returned the car in the same locale.

8. Early Return Fees

This one’s a real annoyance. Most of us would assume that returning a rental car a day or two early would result in us being charged less money, but we would be wrong. In reality, most car rental companies actually charge you more money for bringing back a car early. The “early return fee,” as it is known, usually runs between $10 and $15, but it can be more than that. While that is not a huge amount of money, it is a completely bogus charge, especially when you consider that the car rental company can then turn around and rent out the car you returned early and make even more money off it. If you ask why you’re being charged for returning the rental car early, you’ll likely be told it’s because you’re “breaking the rental contract”. Adding insult to injury, some rental car companies also jack up the daily rental rate when a car is returned early, saying that you no longer qualify for a “weekly rental rate”.

7. Age Penalties

If you’re a young driver under the age of 25, you are considered more of a risk and can be charged more to rent a car, sometimes as much as $25 to $30 more per day. On the other end of the spectrum, if you’re a senior citizen over age 70, you’re also considered a risk to rent a car to and can be subjected to the same additional fees. In some places, the “senior surcharge” applies to people over age 65, and in some places, people over age 70 are not even allowed to rent a car. Often times, car rental companies will not explain the age penalty or surcharge to you. They’ll just ask for proof of age and then, based on how old you are, tell you your daily rate. It’s best to know going in that there is an age factor when it comes to renting a car. Call it “ageism,” or “discrimination” if you want, but age is another reason for car companies to screw you on the rental cost.

6. Frequent Flier Fees

Thinking of renting a car with your frequent flier points? You should probably think again. Most car rental companies will charge you a fee for the privilege of using your frequent flier points to rent a car. Also, rental car companies will charge extra simply for giving you frequent flier points with your car rental. Bottom line, car rental companies hate frequent flier programs, and they will pass on their hatred to you, the customer. Of course, the frequent flier fees are never explained to people. You’ll just get hit with a fee, and if you ask about it, you’ll be told it is a “processing fee” they charge for dealing with the frequent flier company. If this sounds like total garbage to you, it’s because it is. Be aware and save those frequent flier points for when you can use them without any penalties being applied.

5. Peak Season Surcharge

If you’re planning on renting a car in the summer, chances are you’ll pay more money during the months of July or August. That’s because those two months are considered “peak season”, and car rental companies use that as an excuse to charge you $5 to $15 more per day to rent a car from them. This applies to any size of car too, from sub-compact to monster SUV. Complain, and the car rental company will tell you that rental cars are in high demand and scarce at that time. Never mind the fact that the car rental companies always add more cars to rent whenever they need them. You should also know that some car rental companies will charge extra to rent a car at certain times of the day, which they consider to be “peak times”. It can often be cheaper to rent a car at 2 p.m. than at 8 a.m. or 5 p.m., which the car rental companies claim is the busiest time of day.

4. Additional Driver Charge

Even if you and your partner are planning to both drive the rental car, it’s best not to tell the rental company that fact. This is because adding more than one driver to a rental agreement results in, you guessed it, an additional charge. Car rental companies will slap a surcharge on your rental agreement faster than you can say “common law spouse” if they find out more than one person will be driving the rental car. This additional charge can be as much as 50% of the rental cost, which is just ridiculous. A few enlightened car rental companies such as Avis and Enterprise will allow a renter’s spouse or domestic partner to drive the rental car for no extra charge, but only in certain locations. Be sure to check the rules in the jurisdiction where you`re planning to rent a car. Or better yet, just don`t mention your partner. It`s cheaper to be deceptive.

3. Gasoline Charges

The bane of every car renter`s existence is the dreaded gasoline charge. If you`re returning a rental car, then you had better ensure the gas tank is full, and we mean FULL. Otherwise, you will be hit with an enormous premium for returning a car with an empty, or even half empty, tank. The amount the car rental companies charge for gas is borderline criminal. They often will charge double the price at the pump to fill up a car you return with an empty tank, even though, in many instances, the car rental company is situated right next door to a gas station. Too many renters learn the hard way that rental companies charge way too much money for gasoline. By stopping at a gas station on your way to return a rental car and filling the tank with gas, you will be saving yourself a ton of cash.

2. Insurance

Hands down the most common, and evil, car rental fee involves insurance. Typically referred to as “Collision Damage” or a “Loss Damage Waiver” by the car rental companies, insurance on a rental car can run you $10 – $30 per day, on top of the rental rate and all of the other applicable charges we’ve run through on this list. And you can expect that the car rental companies will try and charge you for every little thing on a rental vehicle. For example, did you know that water spots on the side view mirrors can be considered damage? The good news (if there is any) is that car rental insurance is optional in most U.S. states and Canadian provinces, although in some foreign countries it is compulsory. If you are lucky, your regular car insurance will cover you for a rental car, as most car insurance policies today cover people for a domestic rental car. Some credit cards also provide car rental insurance, if you rent the car with your card. However you manage it, it is always best not to take insurance from the car rental company, especially since it’s fairly easy to avoid it.

1. The Little Extras

Does the car you’ve rented have a roof rack? How about built-in GPS? Did you turn on the rental car to find that you have satellite radio? If yes, get ready to be milked like a cow. That’s because you’ll be charged for each and every added feature in the rental car, and we mean every feature. Ff your rental car has built-in GPS, you can expect to pay an extra $25 per day. We won’t even tell you what you can expect to pay if the car has a sunroof. All the cool, nifty little things in the rental car that you find enjoyable and wish were included in your everyday car back home will literally bleed you dry when renting a vehicle. The car rental company adds these extras to their rentals and then uses them as an excuse to treat you like you’re an ATM. Never be shy about telling the car rental company you want the most basic model of car they have on their lot. Your wallet will thank you.