It can come as a huge surprise to many people with spotless driving records that their car insurance rates are high — or they may be denied coverage — because they’re late with the Visa card payment a couple of times a year.

What, they might ask, does my tardiness in paying Visa have to do with my car insurance?

A great debate

It’s a highly debated issue, but many insurance companies and some academics feel strongly that a mediocre or bad credit rating means you’re a high risk. Many consumer advocates, state legislators, and state insurance regulators think not. The debate may go on for quite awhile because even the true believers admit they don’t know why the two are related — they just know they are.

Nonetheless, almost all auto insurers use credit information to decide whether to issue a policy on your car. In some cases they also use it to set the premium.

Bad credit, higher rates

A consumer with bad credit is going to pay 20 to 50 percent more in auto insurance premiums than a person who has good credit. On the other hand, having sparkling credit could land you lower rates, so you should shop around if you’ve got a glowing credit report.

To factor in credit ratings, insurance companies use either the FICO three-digit credit score alone; order an “insurance score” from FICO; or create their own, proprietary score using FICO credit scores or FICO insurance scores and adding in their own underwriting criteria.

The companies generally do not look at your actual credit report. Instead, it receives your credit score or your insurance score from one or more of the three major national credit repositories, Equifax, Experian and TransUnion.

Insurance score likes stability

The two types of scores — credit and insurance — are quite different. An insurance score is going to be less concerned with your propensity to take on new credit and more interested in how long you’ve been managing credit. Insurance scores focus on issues of stability.

Ironically, someone with a flawed driving record but a clean credit record could pay less for auto insurance than someone with a spotless driving record but a spotty credit record.

So as with auto financing, it’s important to know what’s in your credit file and to make sure the information is accurate.

Bad news

The bad news is that while it’s easy to get your credit score, it’s almost impossible to get your insurance score. Companies are not required by law to hand it over, and most don’t.

If you’re having credit problems, it’s best to stick with your current insurer until your credit record improves. If you must shop for a new policy, ask the insurer if it uses credit data in the decision-making process.