If you want to pay off your credit card balance at a lower interest rate and your card issuer won't give you one, a balance transfer might be a good option. But, just because the interest rate on the new card is lower doesn't mean you'll actually save money with the balance transfer.
When you're calculating the savings of a balance transfer, you have to also think about the balance transfer fee and any difference in annual fees with the two credit cards. What's the Cost of a Balance Transfer? will help you figure out whether it's better to leave your balance where it is or move it to a new credit card.
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Yes, it’s possible to get a horrible surprise from the bank for that balance transfer!