Car owners guide to: Car Security > Alarms & Thatcham Ratings

With vehicle crime escallating out of control in the late 1980s, the efforts of government and the British insurance industry led to the setting up of procedures to assess and improve the level of vehicle security provided by the vehicle manufacturers and from 'aftermarket' (that is, items fitted after the vehicle has left the production line) suppliers and installers.

The Motor Insurance Repair Research Centre (MIRRC), or "Thatcham" as it is widely known (taken from its Berkshire location), was established in 1969 by British Insurers. It was given the job in 1992 of developing a set of guidelines aimed at improving the effectiveness and reliability of various forms of security devices, from steering wheel locks to audible car alarm systems.

Thatcham not only puts in place the "goal posts" in terms of the test guidelines and effectiveness each device (or vehicle) must be capable of achieving, it also carries out the actual testing of those devices and vehicles. This includes attack tests on the vehicle and laboratory tests on the vehicle security system's components. The attack tests include breaking into the vehicle through the boot, bonnet or doors, overcoming steering locks and trying to start the engine without the original vehicle keys. This results in a points score.

Thatcham's work is funded by charges made to the companies seeking to have their products certified, and by the motor insurers. Its efforts were extended to include commercial vehicles in 1996/97 and motorcycles in 1999.

While best known for testing vehicle security systems, "Thatcham" also provides a large amount of the data that insurers use to define a car's insurance grouping.

Thatcham Car Security Categories and Installation Certification

The simplest form of car security is the steering wheel lock. At best this provides a limited deterrent but the better ones have been categorised by Thatcham as Cat-3 devices (Category 3 - Mechanical Immobilisers). Wheel Locking Devices (locking wheel nuts/bolts) come under Category 4 (Cat-4).

Vehicle engine immobilisers are Cat-2 (Electronic/Electromechanical Immobilisers) and full alarm systems are Cat-1 (Electronic Alarm and Immobiliser combined). There is also a 2-1 category, which refers to a security system that upgrades a Cat-2 (immobiliser only, often fitted as standard) to Cat-1 by adding the siren, internal movement detection, battery back-up and other features essential to achieve Thatcham Cat-1 accreditation.

As car security systems improved, the career thief found vehicles harder to steal and so moved towards theft using the vehicle's original keys stolen from homes, offices, pubs and clubs. Also, higher value vehicles attracted special attention and no alarm or immobiliser can withstand a determined, well equipped thief indefinitely. This gave rise to the development of Vehicle Tracking Systems (officially tagged as 'After-Theft Systems for Vehicle Recovery') as an effective way of recovering stolen vehicles. These are categorised by Thatcham as Cat-5 devices.

The required specification for each of these categories, along with lists of Thatcham approved security devices, can be found here under The British Insurance Industry's Criteria for Vehicle Security.

To conform to these categories, the manufacturers are required to build their products to very stringent criteria, and every product is subject to annual review. But with aftermarket devices, the product itself is only one half of the equation, with proven expert installation also being a requirement.

Installation by a certified company must be proven. Unless these products are fitted by a certified installer, they are not recognised by the insurance companies. So even if you have a Cat-1, Cat-2 or Cat-5 device on your vehicle, you could find that a claim you make may not be settled in full, depending on the circumstances, if you don't have an installation certificate. You will normally also need to present the installation certificate to take advantage of any discounts off your annual premium, where offered.

Alarm manufacturers often place an installation certificate in the box for convenience. These can be from one of a number of federations (VSIB, MESF) but all must be stamped to be valid. If the security device has been fitted by an unauthorised installer, the certificate will NOT have the proper embossed or other clearly identifiable certified stamp and is thus worthless.

New Vehicle Security Ratings

The 'New Car Security Ratings' (NCSR) scheme was launched in 2001. Newer vehicles (i.e. since the scheme launched), including vans and trucks, as well as cars, are assessed by Thatcham for insurance group rating purposes. The results are derived from a thorough and scientific programme of destructive 'real world' attack testing but have been condensed down to a simple-to-understand star rating for consumers. Potential car buyers can check this online, giving them a broad indication of the vehicle's vulnerability (or resistance) to being stolen (theft of) or being illegally entered (theft from).