Motor insurers in the UK place a limit on the amount that they are liable for in the event of a claim by third parties against a legitimate policy. This can be explained in part by the Great Heck Rail Crash that cost the insurers over £22,000,000 in compensation for the fatalities and damage to property caused by the actions of the insured driver of a motor vehicle that caused the disaster. No limit applies to claims from third parties for death or personal injury, however UK car insurance is now commonly limited to £20,000,000 for any claim or series of claims for loss of or damage to third party property caused by or arising out of one incident.
Some classes of vehicle ownership, or use, are "Crown Exempt" from the requirement to be covered under the Act including vehicles owned or operated by certain councils and local authorities, national park authorities, education authorities, police authorities, fire authorities, health service bodies, the security services and vehicles used to or from Shipping Salvage purposes. Although exempt from the requirement to insure, this provides no immunity against claims being made against them, so an otherwise Crown Exempt authority may choose to insure conventionally, preferring to incur the known expense of insurance premiums rather than accept the open-ended exposure of effectively, self-insuring under Crown Exemption.
Providers can also offer sub-divisions of auto repair insurance. There is standard repair insurance which covers the wear and tear of vehicles, and naturally occurring breakdowns. Some companies will only offer mechanical breakdown insurance, which only covers repairs necessary when breakable parts need to be fixed or replaced. These parts include transmissions, oil pumps, pistons, timing gears, flywheels, valves, axles and joints. 
Over eighty years of insuring drivers has made us one of the most trusted names in the industry. We didn’t become the nation’s third largest insurer by simply offering cheap car insurance prices. We did it by offering 24/7 world-class customer support, and earning an A+ superior financial rating from A.M. Best when it comes to servicing claims. That’s why 4 out of 5 customers recommend Progressive.†† And that’s how we’ve earned the confidence of over 18 million drivers.
But liability coverage levels come in threes — you’ll probably see something like 50/100/50 up to 250/500/250 in typical policies. You can think of these limits like: individual injuries / total injuries / property damage. Insurers are a little more technical, calling them bodily injury liability, total bodily injury liability and physical damage liability.