If you have sworn off credit cards or simply prefer to make some or most of your routine purchases with a debit Visa or MasterCard, watch out. Although paying by debit card is highly convenient and caries a number of advantages, there are a few pitfalls of using debit cards. Some you may already know about; some you may not.

Debit card danger #1: Fraudulent transactions take your money.

If a credit card is lost or stolen, you don’t lose access to any of your money, but that isn’t the case with debit cards. Like a credit card, if your debit card is ever lost or stolen and then used fraudulently, your bank will most likely get most, if not all, of your money back. Trouble is, the investigation into the fraud could take many days, and the money is already missing from your account. What if you need it? What if you have an automatic debit schedule while your funds are missing and you get hit with overdraft fees? You might be out of luck.

Debit card danger #2: Holds tie up your money.

Have you ever noticed signs at gas stations announcing that they may place a hold on your credit or debit card for up to 72 hours? When you swipe your card in a gas pump, it doesn’t know how much gas you’ll buy, so it authorizes your card for $50, $75, or even $100. On a credit card, the pump reserves that amount of credit from your credit line. With a debit card, it actually places a hold on that money in your account. Even if you only buy $10 of gas, you may not be able to use $100 of your money for up to two or three business days—the length of time it takes many electronic transactions to clear your bank. That spells trouble if your bank account balance is low and you need access to that cash. Good news is there’s a workaround: Pay for your gas inside, where you can tell the clerk you only want $10 worth. A bigger problem arises when you try to rent a car or book a hotel room with your debit card. The holds these companies place on your card—often for hundreds of dollars—can take up to two weeks to be released.

Debit card danger #3: Overdraft fees.

Debit cards that are not pre-paid are tied directly to your bank account. You can spend what you have in your account, to a point (see danger no. 4). Therefore, if you’re not keeping careful track of your spending, it’s possible you could try to spend more than you have available. If this happens, you would expect that your card would be declined. Sometimes this will happen, but your bank may also let your transaction go through and instead ding you with an overdraft fee of $30 or more. Ouch. The best way to avoid such fees is to make sure you don’t overdraw your account, but you may also be able to sign up for overdraft protection that will greatly reduce the amount you pay should you do it.

Debit card danger #4: Spending limits.

Many people wrongly assume that just because they have the money in their checking account, they can go out and spend that amount on their debit card. Many times, that isn’t’ so. Most banks impose transaction and/or daily spending limits on debit cards. It may be $1,000, $2,000, $5,000 etc. That means you may not be able to buy an expensive flat screen TV with your debit card. To avoid an embarrassing situation, be sure to check with your bank before going on any high-dollar spending sprees with your debit card.

Debt card danger #5: Convenience fees.

A final debit card danger is so-called convenience fees some organizations will charge to accept plastic. Usually between two and three percent of the transaction, convenience fees essentially cover the merchant’s cost of accepting plastic. Convenience fees affect credit cards, too, but if you’re paying with a debit card it’s easier to avoid the convenience fee and pay by check since you already have the cash available. Also, the practice of charging these fees (or in any way charging credit/debit card customers more than cash customers) is illegal in many states. That said, there is no shortage of places still doing it.