Your FICO score will likely decrease -- how much is impossible to say.
Here are (some of) the reasons why:
- Your old loan likely had a lower utilization -- say you owed $15,000 on a $25,000 initial balance. Now you owe $15,130 out of $15,130 or 100% utilization.
- Your new loan lowers your AAoA when it reports. This could be minor (a few points) if it dropped from 6.3 years to 6.1 years, or it could be major if your AAoA dropped from 5 years to 9 months.
- You likely had an inquiry or batch of inquiries from applying for the loan. These will hurt less in 6 months and have zero hurt in 12 months even though they will report for 24 months.
- The old loan may not report as $0 immediately, so it may affect DTI until it reports as $0 -- this has no effect on FICO but can have an effect on credit seeking until the old loan reports $0. Make sure to call and hassle the old bank every 2 weeks to make sure they don't mark you as late because they didn't receive the payoff.
So basically based on your profile, the new loan could drop your FICO scores anywhere from 10 points to 30 points -- it could be worse or better than that if your profile is really thick or thin.
