I have several different cards. Most are for individual stores. I have 2 major cards which I use for all my other purchases. I use one of them 85% of the time, simply because it pays cash back and has a lower interest rate. All my cards are $0 and paid every month.

Question: If you have major credit cards, like Visa & Discover, can using one over the other affect your credit rating? If one uses Visa 90% and the Discover the other 10%, can it lower the score, even if it is paid off every month??