The change in how FICO is measured could make it more expensive for millions of Americans to borrow.
The gap between "high scores and low scores is likely to get bigger," says AnnaMaria Andriotis of the Wall Street Journal.
Nearly six in 10 Americans now have a FICO score at or above 700, which is considered "good" credit.
The Federal Housing Finance Agency this week announced a new rule that will open up competition for which score, or scores, Fannie Mae and Freddie Mac use.
A 740 today may not mean the same thing as a decade ago.
Experian says consumers who let the firm monitor their checking accounts could get easier access to credit.
Once a closely held secret, free scores are abundant.
Mortgage finance giants Fannie Mae and Freddie Mac consider one credit score when determining the creditworthiness of mortgage applicants: FICO. Some members of Congress want to change that by adding a provision to a bank deregulation bill that would require…