Should I cancel unused credit cards before applying for a mortgage?

At one time this strategy made sense and many people received this advice.  That's because the only thing the potential lender could see was that you had a lot of credit available and that created concerns that you might not be able to manage additional credit especially for major purchase like homes and autos.  But that's the way things worked  before FICO credit scoring came into play.  Today, you could actually hurt your credit score if you cancel or close unused credit lines or cards, at least in the near term.  For example, if you have a total outstanding balance of $5,000 on your credit cards and a $20,000 limit on all cards combined, you have a ratio of 25 percent debt to credit ($5,000 divided by $20,000) - generally considered by most lenders to be a healthy ratio.  Then if you cancel $10,000 of unused credit cards your ratio changes to 50 percent.  The new, higher ratio of credit used to credit available will cause your credit score to go down because it raises a red flag about your ability to manage debt.