This conversation comes up often with people that have credit score monitoring or have received a credit report form one of the ever-popular online credit services. 

Q: wondering which credit company you use for pulling reports. I have mine direct from transunion but other lenders have me at 60 points lower than the FICO I have here from transunion which is updated...thanks

1: Time differences.  Small changes can mean a lot to a credit score.  For example some people charge on a credit card all month long and then pay it off every month.  The balance reported when we pull the credit report VS when you do can have a significant impact.  Balances over 30% of the limit start to impact you, over 50% it hits it pretty good and getting anywhere over the 75% level will really change the scores a lot.  These changes can happen only days from one credit pull to another.

2: Score variances.  All mortgage lenders will use all three bureaus, Equifax, Transunion and Experian (the old TRW).  Each of them use their own model of score and they use different variables to create their score model so that can create differences in scores alone.  We all use the middle of the 3 scores so if your TU one is the highest it gets thrown out anyways.  To add to it, there are some credit cards/loan/collections that only report to one or two of the bureaus.  For instance, I have seen a couple collections only reported to one of the bureaus, and that will significantly reduce that score.  Viceversa, you may have good credit that is only reported to one bureau and the other scores don't use that item in their calculation.  The most well known score is the FICO, and like "Kleenex" it has become the branded word for a credit score.

3. Credit score estimates.  The most common source of this issue is that the website type credit reports actually do not pull the true credit scores from the vendors.  In order to save money they have tried to come up with their own calculation models for the credit scores.  The three big guys keep their models a complete secret and only leak out little tips, but nobody is privy to the actual calculations they use.  I have personally talked to many people about this situation and several have researched it further to verify that the score used is a "FICO representative score", not an actual one.  Unfortunately the score models are constantly being tweaked to represent the current economic conditions so there is no way for a model to exactly replicate the real scores and keep up with their changes. Directly from the Transunion website "These scores may evaluate your credit report differently in order to match the company's specific lending guidelines. Consumer credit scores that you can purchase online use formulas that approximate the most common credit scoring algorithm."