You sign up for a card that promises 0% on balance transferred to the card. But…

There may be a 2% to 4% charge for the transfer. At 4%, that’s $200 on a $5,000 balance. That 0% may last for only none months, then jump to more than you’re paying now.

The 0% may apply only to initial balance transfers – the ones you switch when you first apply for the card.

Say you have 3 cards but apply to transfer the balances from only 2 of them, then later decide to include the third. That third transfer may be treated as a cash advance – you’ll be charged super high fees and interest.

If you’re late on a payment, your 0% will vanish so fast that your head will spin.

If you use the card for new charges, the interest will build up faster than you think it will. Monthly payments are usually applied to your zero-interest balance until the introductory offer period ends. Meanwhile, the interest on new purchases keeps added on.

$$ Saver. To see if it pays to switch, unearth all the fees in the fine print and compare them with your current card’s fees.

If you still like the new deal, transferring balances can take as long as 4 weeks,so keep paying off your old card until you get a statement showing a zero balance. Then, cancel that card so you won’t be tempted to use it and run up even more debt.

On the new card, concentrate on paying off the transferred balances as fast as you can.