If everything was left to common sense, the whole business of writing insurance would be easy. All you would need is an assessment of the individual's driving ability. Good drivers have fewer accidents so pay less. Bad drivers are responsible for claims. That's bad for business so they pay more. Except they had to take this simple idea and make it all complicated. Now, every last fact in every accident that's reported, is collected by the insurers and analyzed. If you sat in front of a computer in an insurer's main office, you could do a search and find out how many Chevrolet Tahoes have been involved in an accident on a straight dry road when all the driver had to do was brake to avoid the collision. In fact, it's remarkable what you can find out when you add in time of day, weather, and any other variables you care to pick. Literally, there are statistics on everything. So, if you asked the computer whether it was Professor Plumb in the library with the candlestick, there would be an answer. Equally, if you put a driver of any age, race, religion and gender into any make and model of vehicle in a particular part of the country, with an estimate of the annual mileage, you will see the probability of an accident. The computer models are that precise.

So perhaps it might come as a surprise that one of the factors now considered by the insurance companies is your credit score. This ranks them alongside banks and loan companies, landlords and anyone interested in whether you are likely to pay them. It also matches the interest of potential employers who look at job applicants to see whether they manage their money well. The theory seems to be that people with bad credit scores are more likely to be unreliable employees - perhaps when they are short of money, they are supposed to be more likely to steal? Anyway, insurers also think that a poor credit score means you are more likely to make a claim. This is wrapped up with the ZIP-code weighting. Poor people live in the type of neighborhood where vehicles are vandalized or stolen. They stage accidents to make fake claims. All the usual stereotyping that works so unfairly.

But once you know insurers are going to check your score, you need to take action. A recent survey found there were mistakes in the credit records of 80% of adult Americans. Most of the mistakes were not serious, but enough reduced the credit scores. Remember there are three major companies, Equifax, Experian and TransUnion, so you need to check all three. This is absolutely free. The Fair Credit Reporting Act gives you the right to one free copy of your history every year, and the right to have any mistakes corrected. Once you are sure everything is correct, you can get the auto insurance quote knowing they will be based on the right information. If you have found major errors in you credit history, contact your current insurer without waiting for a car insurance quote. Most companies correct the premiums immediately.