Did you increase your balance on a credit card ? Or take out any additional loans?

Depending on the agency, they use several methods to calculate credit score. I believe most of them look at your overall credit card balances against your allowable limits. If you exceed certain percentage amounts your score may go down temporarily until you pay it down below that threshold.

There could be other reasons of course, but this one sticks out to me because last year I had to make a big payment and I used my credit card. For the month my credit dipped like 40 points, but when I paid my full statement (which I do every month) it went back up.

Hope that helps and good luck!