If you’re holding a hefty balance on your credit card at a double-digit interest rate, it might be tempting to apply for that new credit card promising you 0% interest on balance transfers for anywhere from 12 to 18 months. While it’s definitely a sound idea to pay less interest, don’t be tempted into behavior that will only lead you into deeper debt.

The folks at Credit.com recently did a round-up of 5 Credit Card Catastrophes and “Doing a balance transfer and then making purchases on the new card” topped the list.

The main problem here is the temptation to use that new card and its no/low interest introductory rate to make purchases. This means that, even though that transferred balance isn’t racking up as much interest as it was on the old card, you’re not taking advantage of the low interest rates to pay down the debt.

You notice that the go-to rate (the interest rate you’ll pay when the intro period ends) is 17 percent but you’re not worried because you’ll pay off the debt before the new rate hits. And then you plan to pay your balance off every month. Sweet deal, right?

So when that introductory interest period ends and the rate goes back to at least what it was on your old card, you might have a bigger balance on that new card than you did a year earlier.

Which is of course the entire reason some card issuers offer low interest rates to new customers.

So the thing to do is to transfer that balance and then lock that card away somewhere that makes it difficult or impossible to use. Credit.com suggests the old “freeze it in a block of ice” trick, though we think the truly desperate habitual shopper might still be able to read the numbers through the ice.

5 Credit Card Catastrophies (and How to Avoid Them) [Credit.com]

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