31: Not enough available credit on revolving accounts
Bankcard accounts include credit cards and charge cards from a bank and are frequently revolving accounts. They allow you to carry a balance and your monthly payment will vary, based on the amount of your balance. The total combined amount you owe on all your bankcard accounts is high, resulting in reduced available credit to use if needed, creating a greater chance of becoming overextended.
Paying down the balances on your accounts will benefit your score.