A widely used rating system that assesses the credit worthiness of consumers will change this spring.

The Fair Isaac Corp., or FICO, score rates consumers on a scale from 300 to 850 based on credit histories. A score can mean the difference between getting a commercial or mortgage loan and being denied. It can even affect premiums for auto insurance.

Barbara Read, communications director for the area Better Business Bureau, said the revised scoring system will be somewhat more lenient. In the past, a person would be severely penalized for even a single late payment.

Fair Isaac Corp. public affairs manager Craig Watts said the "FICO 08" formula will be more forgiving of an "isolated" late payment, and harder on people whose report contains several late payments.

"By isolated late payment, I mean one that occurred several years ago and that was neither preceded by other late payments nor followed by other late payments," he said in an email.

Watts said the new version of the scoring formula will continue to emphasize paying bills on time, keeping credit card balances low and obtaining new credit only when needed.

Updating the scoring formula is an ongoing process, he added. "To date we've built four generations of the FICO scoring formula, and the newest version FICO 08 will mark our fifth generation," he said.

A good FICO score is anything higher than 700. The average score for U.S. consumers is about 690, according to the Better Business Bureau. More than 90 percent of the 100 largest banks use FICO scores to determine who they will lend to, and at what rates of interest.

Each of the three national credit reporting agencies - Experian, TransUnion and Equifax - use the FICO formula in its operating system, then uses the formula to calculate and sell FICO scores to lenders, Watts said.

"We understand that Experian and TransUnion plan to begin delivering FICO 08 scores to lenders starting this spring, probably in May," he said. "Equifax hasn't yet indicated when it will begin providing these scores."

Read said consumers can get a free FICO estimate at the Bankrate.com Web site. The Web address is http://www.bankrate.com/brm/fico/calc.asp.

Business Editor Tom Mast can be reached at tom.mast@trib.com, or call 307-266-0574.