With all this recent controversy about changes to FICO credit scores, it is interesting to note that there are other credit scoring models that have always excluded authorized user accounts. According to an Equifax press release, the VantageScore and Equifax Risk Score 3.0 have never included authorized user accounts in their score calculations.

"Being an authorized user on someone else&39;s account does not demonstrate an individual&39;s ability to pay their credit obligations. For this reason, it does not make sense to include authorized users in the calculation of a credit score," said Lisa Zarikian, who leads Equifax Predictive Sciences and was a member of the team that created VantageScore.

If you recall, the VantageScore is a new credit scoring system developed jointly by the three credit bureaus in order to better compete with FICO. Announced in March 2006, the VantageScore has a very limited reach compared with more established credit scoring systems.  VantageScores became available to consumers online last June and use a scale from 501 to 990.

Equifax Risk Score 3.0 is a business scoring model designed in 2004 by the bureau for business clients.  You can read a brochure about the score online here.