How long a DUI will affect your car insurance rates depends on how long the conviction will remain on your driving record, state insurance laws and your insurance company's rating system.
Typically an insurance company can rate for 3, 5 or even 7 years on a violation depending upon how long it remains on your driving record. So if your DUI is off after 3 years than normally it could only be rated on for that 3 year period. If it remains on the abstract for 5 years than it would be up to the rating system of your insurance company to determine if it would be rated on for the full 5 years or less. If they only usually rate for 3 they would do so even though the offense stayed was on your abstract for 5 years.
How long a DUI offense stays on a driving record varies by state. In some it is only 3 years for a first offense but in other states remains for the lifetime of the person's motor vehicle record (MVR). After you know how long the DUI will be on your driving record than next you need to find out what your state insurance laws are regarding how long an insurer can rate you on the DUI.
In some states there is a limit to how many years the insurance company can surcharge you for a DUI being on your driving record (such as 3 or 5 years) however in other states it is up to the insurance carriers' guidelines as to how long they can raise your rates. As long as their rates are filed with the state and approved by the state's insurance regulator the insurance companies in some states can surcharge for a DUI for several years.
In California for instance drivers with a DUI violation occurring within the past 10 years are not entitled to receive a good driver discount under CA Law. Under this law, a driver with a DUI on their MVR may not qualify for a good driver discount again until 10 years have passed from the date of their DUI violation.
So CA auto insurance companies are required to follow the 10 year law regarding the good driver discount, but they can raise your rates or surcharge you due to the DUI for a different amount of time. In California there is no law on if the DUI will affect your rates (beyond that you cannot receive a good driver discount) for 5, 7 or 10 years though the charge is on your driving record for the full 10 years for your insurer to see.
Speak to your insurance agent about how this DUI is affecting your rates and how long it will continue to raise your rates (if it indeed has already). You may want to shop around for cheaper insurance or one that offers more discounts (multi-car, anti-theft, etc) and thus at least helps reduce the affect of the DUI on your driving record.
As you know one will normally see a big increase in their auto insurance rates due to having a DUI conviction on their driving record. Having operated a vehicle while under the influence of alcohol or drugs generally puts a motorist into a high risk class of drivers.
The amount of an insurance premium increase due to having a DUI and/or needing an SR-22 (certificate of financial responsibility) will depend upon the insurance company that you are dealing with and their rating system. You also may lose discounts that you also previously had on the policy which helped to lower your rates, such as a safe driver discount.
Some state insurance regulators and department of motor vehicles give information on the average insurance increase for a DUI conviction. For example, the Colorado Department of Transportation has a Cost of a DUI brochure lists that your CO auto insurance could go up 30 % on average, that is if it is not canceled, after having a DUI conviction. Your state's insurance regulator can also tell you what the average time period is that your rates will be higher for after your DUI conviction.
Shop around to see what the lowest rates you can get with your driving record. Start here with a quote from an auto insurance specialist.