<prompt> Human: Hi rpersonalfinance - I was hoping someone who had a better understanding of all this could give me some insight into how my score could have in my opinion changed so drastically. In September of 2014 I was looking into refinancing my student loans, so I went through the entire application with SoFi to refinance and they accepted me. During the process they ran my credit score and sent me a copy: September 2014 Experian Score: 817 - proof I was extremely surprised! And really happy. Since then, I have NOT changed any of my usual financial habits. I pay my credit cards on time every month. I occasionally leave a balance, but nothing that lasts longer than a month or two, and I ALWAYS pay more than the minimum. Im currently carrying 0 balance on both of my major cards. Ive not made any other major purchases where an inquiry into my credit was needed and I have not been late for any payments on any other loans that I have in my name. Aside from that refinance - my habits have remained the same. Two days ago I went to credit karma to check my credit in preparation for a potential move I need to present myself as a responsible tenant and I found my score to be drastically lower! WTF... June 2015 TransUnion Equifax Scores: 681 - proof What happened here? I understand that the Experian score could be different from those of TransUnion and Equifax; however, could they really be THAT far off? Did carrying some extra balances in one my credit card accounts which has since been paid off really affect my scores this much? Its just been 9 months since these two score reports... is it normal for scores to change that much in that period of time? Im a little concerned because I had planned on applying for new apartments, but I fear that my scores would prevent me from being seen as an ideal candidate.In an effort to give as complete a background on my financial picture as possible here is a little more about me: 30-something male - making 90k per year 55 k in student loan debt which has since been refinanced with SoFi. Have two main credit cards which I use. Currently carrying 0 balance month to month. 30k in savings. Not that this would play into it at all... just giving an overall picture of my financial situation. Credit Limit for AMEX Card 1: 7,000 Credit Limit for VISA Card 2: 5,000I could get into how much Ive got squirreled away in my 401kretirement funds, but I dont feel thats relevant. Can anyone with more knowledge on the subject of Credit Scores and how they can be positivelynegatively impacted provide insight? How do I go about fixing this and getting back to 750?If you need more info from me, please let me know! Im happy to provide. tl;dr - Credit score went from 817 Experian to 681 TransUnionEquifax in 9 months. No changes in any of my financial habits except for one major refinance of student loans. Howwhywhat can I do to fix?  <response>: Sofi uses FICO 9. Credit Karma uses Vantage Score ... 3.0? Completely different companies and scoring models. 