With the newest version of the FICO credit scoring system, minor delinquencies are now overlooked in calculating creditworthiness.

When you close the credit-card account that you’ve had the longest, it will lower the average age of your credit accounts and drag down your FICO Score.

You charged thousands of dollars’ worth of appliances to a store credit card that doesn’t require payments for six months. As long as you make the payments in six months, your Credit Score will not be affected.

Late payments are the “biggest foul” when it comes to credit cards, warns Ben Woolsey, director of marketing and consumer research at CreditCards.com — the consequences can include late fees, jacked-up interest rates and a lower credit score.

Free FICO Scores have become more available to consumers since 2013, when Fair Isaac Corporation announced its FICO Score Open Access Program, which gave banks the right to share a FICO Score with consumers. Additionally, banks claim the free FICO Scores have increased customer loyalty.