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.
Yes, you surely can avail the NCB if you change your insurance provider at the time of renewing the policy. All you would need to do is producing a proof of the earned NCB from your current insurance provider. You can produce the original copy of your expiring policy and a certification that you haven’t filed any claim for the (expiring) insurance plan. A renewal notice or a letter stating that you’re entitled to the NCB from your previous insurance provider can be a proof for this.
 Availability varies. Enrollment discount applies during data collection; final discount is calculated on driving behavior and could be zero. Discounts do not apply to all coverage elements; actual savings vary by state, coverage selections, rating factors and policy changes. Final discount applies at the next policy renewal and remains until drivers or vehicles on the policy change.
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."