Typically, non-owners insurance is additional coverage to give you liability protection for when you are at fault and don't own a vehicle.
The qualifications for using it would be to first have the policy and then it would be limited to the coverage definitions and exclusions in that policy. Those are typically standard to the coverage you have. For example, to get a non-owners policy you would only purchase bodily injury and property damage coverage.
You want to verify that any vehicle you drive is insured. The owner of that vehicle is required to insure it. A non-owners policy would be secondary to that insurance.
You can comparison shop our rates for non-owner policies by getting a car insurance quote here.
Comment Update: There is no legal definition for non-owners that applies to car insurance. Insurance companies file their rates with their respective insurance departments. This is a typical filing, qualification and definition:A non-owner / named-operator policy may be written when the insured needs coverage only for his personal operation of a vehicle not owned by him or a family member.
- Only Liability BI, PD and UMBI may be written
- Permissive operator coverage is not included