Use Your Available Credit
If you have credit accounts but don’t use them they can disappear on you. If your accounts lie dormant for too many years the lender can just remove it at its discretion. Of course every time an open account is removed from your life it is results in a negative credit comment on your credit report.
The best way to maintain your credit is to use a little bit of your credit all the time and pay the balances off on all debts before the due date of the balance.