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 UK law is defined by The Road Traffic Act 1988, which was last modified in 1991. The act requires that some motorists either be insured, have a security, or have made a specified deposit (£500,000 as of 1991) with the Accountant General of the Supreme Court, against their 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.

Insurance which satisfies the requirement of the act, for those who require cover, is called third party insurance. It is an offence to drive your car, or allow others to drive it, without at least third party insurance whilst on the public highway (or public place Section 143(1)(a) RTA 1988 as amended 1991); however, no such legislation applies on private land.

Vehicles which are exempted by the act, from the requirement to be covered, include those owned by certain councils and local authorities, national park authorities, education authorities, police authorities, fire authorities, heath service bodies and security services.

The insurance certificate or cover note issued by the insurance company constitutes legal evidence that the vehicle specified on the document is indeed insured. The law says that an authorised person, such as the police, may require a driver to produce an insurance certificate for inspection. If the driver cannot show the document immediately on request, then the driver will usually be issued a HORT/1 with seven days, as of midnight of the date of issue, to take a valid insurance certificate (and usually other driving documents as well) to a police station of the driver's choice. Failure to produce an insurance certificate is an offence.

Insurance is more expensive in Northern Ireland than in other parts of the UK.

Most motorists in the UK are required to prominently display a vehicle licence (tax disc) on their vehicle when it is kept or driven on public roads. This helps to ensure that most people have adequate insurance on their vehicles because you are required to produce an insurance certificate when you purchase the disc. However, it is a known practice for some people to purchase insurance to gain the certificate and then to cancel the insurance and gain a full refund within the statutory 14 day cooling off period.

The Motor Insurers Bureau compensates the victims of road accidents caused by uninsured and untraced motorists. It also operates the Motor Insurance Database, which contains details of every insured vehicle in the country.