When you apply for a credit card, application that you sign is also a legally binding contract laying out all terms between you and bank, such as interest rate and how its calculated, grace period, whether there’s an annual fee, etc.While you have to agree to terms and sign if you want credit card and while lender will certainly hold you to terms, lender doesn’t feel similarly committed.
Lenders like to constantly amend terms, effectively changing deal after it was made. This is one of few industries where you can be charged more than you originally agreed to pay.
One of main reasons they’re doing this is because they are constantly checking your credit score, looking for an excuse to raise rates and thus their income.
So, even if you have never been late on any payment to any bank or utility, your credit score can raise as you’re approaching your credit limits. Or you could have missed a payment or lost your job. Lenders have any number of excuses for their actions.
Also lenders count on customers not reading little inserts filled with legal jargon they slip in with your bill or mail separately, at least until it’s too late. Apparently vast major of card holders never look at these amendments. Theu also hope that most of us are ignorant of our credit card rights.
Not all changes to credit card agreement are necessarily harmful to you, although you'll rarely find one being done in your interest. Most of them change minor terms of agreement.
But they can contain nasty suprises as well.
The problem lender has is that original agreement is a binding contract that lender can’t change unilaterally. They have to give you an out. That’s why it pays to pay attention and know your credit card rights.
I once had a credit card account with stated interest rate of 13.5%. I was financially strapped and was using more and more of my available debt. I had never missed a payment or was late to anybody for at least 10 years.