You don't just have one FICO score -- you have three. And here's why those scores can vary. By Kimberly Lankford, Contributing Editor April 21, 2011 I read your Understanding Credit Scores column about the difference between the FICO credit score and the VantageScore. I have a similar question about big differences in my credit scores, but in my case both scores were FICO scores. How can my scores be so different when they’re both FICO scores and use the same calculations?You actually have three different FICO scores, based on your credit reports from each of the credit bureaus (Experian, Equifax and TransUnion). Each score is based on information in your credit report, so an error or incomplete information on one report can drag down that version of your FICO score – -- even if your other scores aren’t affected. high. It’s important to check your credit reports from at all three bureaus before you apply for a loan. Some lenders may just pull your credit score from one or two of the bureaus before deciding what rate to offer. But mortgage lenders usually collect get your FICO scores from all three bureaus and base your rate and terms on the median score. If you’re applying for a mortgage with a spouse, the lender will pull all three FICO scores for both of you, then focus on the median score for each person. The lower of those two median scores usually determines the rate and terms of the loan. You’re more likely to ll usually get the best mortgage rates if both spouses have a median score of at least 740. But you may have a tough time qualifying for any mortgage if one spouse has a median FICO score below 620. See Coupling Your Credit for more information. You can get a free copy of your credit report from each of the three bureaus every 12 months at www.annualcreditreport.com. The fastest way to correct errors is to report them to the credit bureau online. Disputes must be processed within 30 days, but are usually settled faster. See Fast Ways to Improve Your Credit Score for more information. Got a question? Ask Kim at email@example.com.