The CARD Act of 2009 requires credit card companies to provide cardholders with 45 days' notice when interest rates are increased. While most credit card users assume this means they'll receive notice at least 45 days before their interest rates rise, this actually isn't the case in most circumstances.
What this new rule really means is that you must have 45 days' notice before you pay the higher interest rate. There's still nothing stopping your credit issuers from increasing the interest rate for new purchases on the 15th day after the notice is mailed.
If you do receive such notice from your credit card company, pay close attention to when the letter was postmarked so you'll know exactly when the new terms take effect. Better yet, make it a practice to always pay your credit card bills in full each month so you can simply look at notices like this, shake your head, and chuck them in the trash.
If you never carry a balance on your credit cards, interest rate changes will mean practically nothing to you.
