Yes, it is illegal and a form of fraud to give false information on an insurance application, especially for the express reason of lowering rates.
According to the California Department of Insurance fraud occurs when someone knowingly lies to obtain some benefit or advantage to which they are not otherwise entitled or someone knowingly denies some benefit that is due and to which someone is entitled.
Depending on the specific issues involved, an alleged wrongful act may be handled as an administrative action by the Department of insurance or the Fraud Division may handle it as a criminal matter.
Trying to obtain auto insurance from your parent's address instead of your own address where the car is actually garaged would be misrepresentation and could get both you and your parents in trouble if done. If you did acquire insurance using their address and this untruth was later uncovered your insurance could be cancelled and if an accident occurred it may not be covered since the insurance policy was set up using false information.
This can also be classified as material misrepresentation which as defined by the DOI is a false statement given by an applicant of any important fact that, had the insurance company known the truth, it would not have insured the risk.
Instead of committing fraud it is best to be upfront with an insurance company and use your correct address. To try and cut costs for your auto insurance ask about discounts or if there are driver programs in which to participate so that you can reduce your premiums.
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