Most people like debit cards due to convenience and/or an aversion to the use of credit cards.
However, there are at least two pitfalls with debit cards that everyone should be aware of:
1) If you use your debit card at a gas pump, you may only pump $20 worth of gas, but don't be surprised if as much as $75 is frozen in your account.
link The length of time that the 'freeze' remains is up to your bank, but the amount is up to the gasoline retailer.
There are other instances where cards are used in this manner as well, such as when renting a vehicle or reserving/checking-in a hotel room.
2) If you are ever charged more that you were supposed to be charged, or someone uses your card or number illegally, be prepared for lots of hassle. For instance, the law limits consumer liability for credit card fraud to $50. For debit card fraud, your liability is $50 if you notify the bank with 2 days of learning of the fraud (receiving a statement), and $500 or more after two days, up to the entire amount stolen under certain circumstances.
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Also, while there are protections in place, your other checks could bounce and you could face bounced check fees, bad credit reports, cash flow problems and other hassles. (Unlike with a credit card where you simply fight with the bank about getting disputed charges off your account, not getting your own money back.)