Say, there is a conviction in an insurers' database, what happens once 3 years passed? Is it going away automatically, or the company keeps it forever?

And in more detail: If there is an another conviction on a profile and if after these 3 years, another one happens, will these convictions sum-up on the profile and affect rate calculation?

I think that would be dependent on the company/policy, each is likely different.

It wouldn't surprise me if they kept your conviction history on file forever (data storage is cheap), but they simply choose to overlook it after X years.

Insurance companies are prohibited from "permanently" retaining your information and using it to determine your rates.

Generally, your first minor conviction will have little or no impact on your rates. But if you have had a second minor conviction in the last three years, it will most likely affect your premium. If you have had accidents where you are more than 25 per cent at-fault over the last six years2, or a number of minor driving convictions or even one major or serious conviction over the last three years, your premium will be higher. Likewise, the better your driving record, the lower your premium will be.

That's from the Financial Services Commission of Ontario, which regulates the insurance industry.

www.fsco.gov.on.ca