[vsjhoc]

I agree with the keep-it-under-35%-of-your-credit-limit rule.

As far as your credit score is determined, it doesn't matter whether you pay the balance in full each month or not, provided you pay at least the minimum due by the due date.

What matters is what your balance is on the day that the credit card company reports it to the credit bureau. Say you have a limit of $1,000 and you charge $500. Your due date is on the 31st, and you pay the whole $500 on the 29th. But if your credit card company reports to the bureaus on the 28th, your report will show that you have a balance of $500, and your credit score will calculate it as 50% utiliization on this account. It doesn't matter that you pay the whole balance off the next day, even before the due date. So try to find out what day of the month your accounts are reported, and make your payments accordingly (making sure you don't inadvertently make a late payment, of course!).