To reduce the insurance premium, the insured party may offer to pay a higher excess (deductible) than the compulsory excess demanded by the insurance company. The voluntary excess is the extra amount, over and above the compulsory excess, that is agreed to be paid in the event of a claim on the policy. As a bigger excess reduces the financial risk carried by the insurer, the insurer is able to offer a significantly lower premium.
In 1930, the UK Government introduced a law that required every person who used a vehicle on the road to have at least third-party personal injury insurance. Today, this law is defined by the Road Traffic Act 1988, (generally referred to as the RTA 1988 as amended) which was last modified in 1991. The Act requires that motorists either be insured, or have made a specified deposit (£500,000 in 1991) and keeps the sum deposited with the Accountant General of the Supreme Court, against liability for injuries to others (including passengers) and for damage to other persons' property, resulting from use of a vehicle on a public road or in other public places.
A compulsory car insurance scheme was first introduced in the United Kingdom with the Road Traffic Act 1930. This ensured that all vehicle owners and drivers had to be insured for their liability for injury or death to third parties whilst their vehicle was being used on a public road. Germany enacted similar legislation in 1939 called the "Act on the Implementation of Compulsory Insurance for Motor Vehicle Owners."