I was reading, I think in Motley Fool, how people should have a few credit cards just to maintain a credit score. I bought my first house late in life, with no other debt, an only a debit card. I was asked for records from bills like phone, rent, and power showing I paid my bills on time. It seemed like enough to qualify for a loan on my first home mortgage. I've never really thought much about a credit score, but it seems important that you pay off debt payments on time regardless of whether you just forgot, or it's unaffordable.