<prompt> Human: I have the discover IT card. I have made all my payments on time and in full with no problem what so ever. My score was a 690 last month, but after this payment, its a 675.Can someone explain this to me?Assistant: Go to Credit Karma, its free and shows you if you have other accounts or anything else that would be negatively impacting your score. Are you blindly saying yes when retail associates are asking for your social security number, and opening new lines of credit? Also, your Discover IT app, where it shows you your FICO score, you can click on the score box and it will tell you the key factors that affect why its lower than you expect.Human: just a note - Im on Credit Karma. It says my credit score is 765 for TransUnion. I bought a car the other day and they came back from TransUnion with a credit score of 675. After doing some research it turns out Credit Karma isnt entirely accurate. Assistant: My family members keep telling me that CreditKarma is total BS. My brother used it when he moved out of state and his credit was a huge difference as well.Thanks for confirming this  <response>: Its not, its a great tool, when you understand it. A key piece of data is that there are different rating systems at play here. FICO and Vantage to name just two, FICO being the most common, Vantage 3.0 being what Mint is using. They WILL vary because they are built differently, but base off of the same information. I use CK regularly. Are they an exact match? Nope, not since CK switched from FICO to Vantage , but you do get a good look at whats on your report, and following it regularly can help you make better decisions. Just ignore all of the ads.Have you applied for any other credit lately? 20 utilization isnt bad, 10 is ideal, over 30 is a red flag. New accounts? Missed payments? 