I got a notification from a credit reporting bureau earlier this week that my FICO score dropped 11 points because my revolving credit utilization increased from 1% to 2%. Mind you, this for a card I have paid off in full every month for 2+ decades.Yeah CC is the big one...I can tell you when I don't pay my CC off fairly quickly and put a big charge on it the score drops more so than you would think...even when you pay it off quick you only gain a percentage of that back..