I can't count the number of times I pre-approved people before the Holidays, only to see their credit scores have dropped by the time they find a home during the Spring market. The culprit you ask, why its excessive Holiday spending of course. Lets face it, we as red blooded Americans spend to much money, a lot of which is credit debt. This just in, revolving trade lines (i.e. credit cards) that have a balance of more than 50% of the limit WILL LOWER our credit scores. Credit cards that are maxed out with consistent minimum payments is a sure fire way to have the old credit scores in the low 600s. I won't bother to insult your intelligence by telling you the impact of late payments on our precious ficos.
I know what your thinking, "but Steve, I'm doing a conventional loan with 10% down and the rate is the same whether my credit score is a 600 or an 800." Well not any longer! New guidelines from Fannie Mae and Freddie Mac for most conventional mortgage products state that rates will be based on credit scores. If your credit score is under a 680, your rate will be higher. If your credit is below 680 and you desire to have a rate dictated by a 680+ score, it will require an additional fee in the way of "Discount Points". That fee will represent exactly where your score is.
I want wish everyone a "Happy and Safe Holiday Season"!