One not-so-great fact about debit cards: Transactions don't always show up immediately. So there's your "balance" and your "real balance."
Often with signature-based purchases (the ones that don't involve your PIN to complete the transaction), the money can take up to a few days before it exits your account, says Dosher.
The solution: Keep track of your true balance via receipts and a checkbook, ledger or even a cheap notebook. And yes, there's an app for that -- for your iPhone or Android system.
Also check out the online banking services offered by your bank or credit union, Dosher says.
But online doesn't necessarily mean "real time." With some institutions, there can be a delay, even with online banking, before some transactions appear on your account records.
Returning a debit card purchase? You may have to wait for your money.
"Typically, it's not more than a week, and as little as a day," says Butler. "You really have to ask each retailer because it varies," he says. "And it varies depending on which bank you're using and which bank the retailer is using."
So if money is tight -- and you suspect those new jeans will be, too -- using cash or credit might be smarter.