How would my credit score drop 7 points in one day? I didn't change anything, how can I find out what changed?
Sums it up well!
Did any of your balances go up or CL go down - increasing util%?
Did any old account fall of your CR - decreasing average age?
Did an inq from the psst finally hit CR - sometimes they are delayed?
Did an account you recently opened finally hit CR - sometimes they are delayed also?
Did you recently pay off a loan - thus changing your credit mix?
If you literally have had no new activity in last 6 mo (no new cards, no inq, no CL decreases, no accounts closing, no accounts dropping) then most likely is an increase in REPORTED balance.
Not I said REPORTED. Let's say you PIF on a card each month. It's a 2K card and you put about 500 on it. Every month you pay it around the 23rd-26th and it reports on 28th. So when it reports it has maybe $100 on it. This month you end up paying on 29th so it reports 600 on $2000K = 30% util. Score gets hit 7 points. Nothing changed except the date of payment.
As sidewinder say look at CR before and after change.