I am not an official credit card counseling person but the longer your cards are open and are in good standing then the better it is for your credit rating. Also, it is better to have less than 50% balance on any one card. For example, if you have a $10K limit on one card and a $20k limit on the other and want to borrow $15K, it is better to put $5 on the first card and $10K on the second card instead of all of it on the second card with the bigger limit.