Don't Lose Your 0% Balance Transfer
You may forfeit your 0% balance transfer offer if you make a late payment, have a payment returned, or exceed your credit limit during the promotional period. If that happens you will trigger the default rate on the credit card balance.
You may not get the full benefit of 0% balance transfer if you transfer to a credit card that already has a balance or make purchases on your credit card. That’s because your above-minimum payments will be applied to the credit card balance with the highest interest rate.
0% Balance Transfer Benefits
The best way to take advantage of a 0% balance transfer is to pay off the balance before the promotion ends. That way, you dodge paying interest on the balance transfer. Avoid making purchases on the credit card until the balance transfer has been completely repaid.

