What is SR-22 insurance and how does it work?

Though sometimes referred to as a type of car insurance, an SR-22 is simply a document high-risk drivers sometimes have to file via their insurance company in order to prove they have the legally-required minimum amount of car insurance coverage. Not everyone will need to file an SR-22. Generally, they're required for those who have been ordered by their state.

If you find yourself scrambling to find car insurance (whether for court-mandated reasons or otherwise), consider one of CNBC Select's top picks for car insurance companies for high-risk drivers.

Our best overall insurance company for high-risk drivers is State Farm, which offers affordable rates for situations like DUIs or DWIs and those with at-fault accidents. In addition, it boasts high customer satisfaction ratings. For those with DUIs or DWIs, Progressive offers affordable rates and coverage. Both Progressive and State Farm support SR-22 forms. 

Here's what else you need to know about SR-22 forms. 

An SR-22 is a form that your car insurance company files with your state that proves you have enough coverage to meet the minimum coverage required by law. Minimum car insurance coverage requirements vary by state, but you can count on needing liability coverage in most cases (as opposed to full coverage insurance, for example).

It may also be called a certificate of financial responsibility or an SR-22 bond. In Florida and Virginia, this form is called FR-44, which is similar but requires higher levels of car insurance than the state minimum. 

With both forms, you can expect to have to file them with the state for at least three years, though the specific time will depend on the state you live in and the nature of your offense. 

Generally, you'll find out that you need an SR-22 during a hearing in court, or by a letter from your state's department of motor vehicles. 

There are a few common reasons that require you to file an SR-22, including: 

• A DUI (or DWI) 
• Driving without enough insurance
• Repeated traffic offenses 
• An at-fault accident where you didn't have insurance
• Failure to pay child support
• Having a hardship license after your license has been suspended or revoked

However, SR-22 laws vary by state, and different states have different requirements for SR-22 forms.

You may be required to have an SR-22 form on file even if you don't have a car. An SR-22 form from a non-owner car insurance policy could help you stay compliant even if you don't own a car. 

The SR-22 form itself is relatively inexpensive — insurance companies generally charge about $25 to send the form. Only your insurer is able to send the SR-22 form for you, and you'll likely need to inform your insurer that they have to file the form on your behalf. 

How much you pay for your underlying car insurance premiums, however, will depend on what made the SR-22 form required in the first place. If you were involved in several at-fault accidents or have a DUI or DWI on your record, you may pay more than someone who didn't pay child support, for example. 

It's still possible to make sure you're getting the best possible rate for your situation, however. To do this, you'll want to shop around for insurance. Get car insurance quotes from several different insurance companies and compare the offers. To accurately compare insurance quote premiums, or the amount you'll pay for coverage, make sure the types of coverage offered, the limits available and the deductible are the same.

An SR-22 isn't insurance at all — it's a form that your car insurance company needs to file with your state motor vehicles department that verifies your coverage. Depending on your situation, it may increase your car insurance costs and there's generally a small fee for your insurer to file the form.

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