What happens if you are driving someone else's car and you have an accident and do not have proof of insurance?

If should be sufficient to tell the Police that you have a policy which allows you to drive other cars and give them the name of the company, they can then advise you to produce your documents within a certain lenght of time or they can ring the insurance company and confirm the details on the spot. . If the police havent been called then just get the other persons details and give them yours and tell them youll ring them later on with the details of your policy! If you dont have insurance to drive the other persons car then any accident caused by you will effect their insurance and may mean that they cant claim for the damage to their own car as they let an uninsured driver drive it! If they say they didnt give you permission to drive then you will have to be prosecuted for theft before they can claim for their damage!! Hope this helps!