Having been in the mortgage processing business, I take over from the Realtor and Loan Officers, to get your Mortgage loan approved and funded, there is a whole long list of items that can affect your credit rating,
1.having your credit pulled by
a car dearers
b insurance agents, even if they tell you it won't, it will
c credit cards
d. OR even you!! If you look at it more than 1 a year, you will lower your scores.
I learned a new thing about credit cards!! If it says payment due may 1st,but they have a grace period for payments,anything after the 1st is still considered late even if you paid it, they will still report it late!!! So, may sure ALL payments are paid by the due date!! Especially Mortgage and Credit Cards payments.