"They look so attractive because it looks like all you have to do is fill out that check and you get some free money," says Bill Hardekopf of lowcards.com.
But as Hardekopf reminds us, you've got to read the fine print.
"And what you'll see is that they usually come with a fee of anywhere from 3 to 4, maybe even 5 percent on whatever your write the check for. So, they become a very costly way of charging something," he says.
That's because the interest charge may be significantly higher than the APR on your credit card. And remember, that interest kicks in right away.
"There's usually no grace period with a convenience check as there is on a credit card purchase," Hardekopf says. "Your interest will begin to accrue from the day that the check clear the bank."
Bottom line: convenience checks may be handy, but you'll pay for that convenience.
More Information: Understanding Convenience Checks