When you’re traveling and can’t rely on public transportation, renting a car is a convenient option. However, it can also come with a higher-than-advertised price tag when you add in the fees and optional services you might not actually need.

From fuel surcharges to so-called convenient toll services, there are no shortage of ways in which car rental companies try to get their hands deeper in your pocketbooks.

Writing for USA Today, consumer advocate Christopher Ellliott notes that there are rental car add-ons — some that even savvy consumers might be unaware of — that can leave you paying more for your vehicle.

Here are three tactics rental car companies often use to add to your bill, and what you should do to avoid paying more than you need to.

The Quick Upgrade 
Many car renters seek out the cheapest available vehicle, generally a compact or economy sedan. However, those aren’t always the most comfortable cars, and the option to upgrade might seem attractive, especially if it’s free.

But that might not actually be the case. In a tactic, known as a “sign here” ploy, a car rental employee will offer a customer an upgraded vehicle without mentioning a price difference. The customer will then sign the rental agreement, which includes in the fine print a price per day for the upgrade.

One man tells Elliott that he unknowingly agreed to a $11/day upgrade fee recently. In this case, the man says he was offered an upgrade without any mention of a price difference. After returning the vehicle, the man noticed his bill was $162 more than he was quoted when booking.

To avoid this tactic, ask the rep directly if the offered upgrade is coming with an additional fee and read the agreement.

Paying More For Less
Many car rental customers attempt to pay less for more by renting the lowest tier vehicle in hopes that when they show up to pick up the car, only larger options are available.

As a rule, most car companies will upgrade customers into the next tier if the reserved vehicle isn’t available. However, Elliott reports this isn’t always happening.

Instead, some agencies are listing a sedan at a lower rate online, but when the customer shows up the vehicle isn’t there. In its place, the company will offer a lesser vehicle for the same price.

Elliott suggests that customers remind the company of their general practice to upgrade for free when a reserved vehicle is sold out.

Unnecessary Insurance 
A long-standing tactic used by car rental companies involves selling customers on added insurance packages. Over time customers have caught onto the ploy, refusing the policies and the fees they come with.

But the companies have also caught on, Elliott reports, revamping their sales pitch by refusing to rent a vehicle unless the customer buys the add-on.

However, Elliott reminds customers that if they own a vehicle, they likely already have insurance that will likely cover their rentals.

If a company refuses to rent you a vehicle without an added insurance policy, show them a copy of your own insurance plan. If they still refuse to provide you with a vehicle, it might be best to take your business elsewhere.

For more tactics used by car rental companies, including added fuel fees, check out Elliott’s full list of car rental tips.

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