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We quite often get asked by customers what the different ‘Thatcham categories’ mean. Generally, the higher Thatcham rating the security systems on your vehicle are, the more your insurance could come down (as your car should prove harder to steal or break into).
Here is an explanation of the Thatcham categories for alarms, immobilisers, vehicle trackers and other security systems:
Systems that fall into this class are the cleverest and most complex on the market. A Category 1 alarm will feature perimeter and ignition detection, and will incorporate movement or glass break and tilt sensors. There will also be a siren powered by its own battery supply that will sound if your car gets broken into.
Immobilisers are also a requirement to pass Category 1 tests and have to be passively set – that means without any action from the driver – while a minimum of two operating systems or one control unit used for normal operation must be isolated.
Alarms are not a requirement to be awarded Category 2 Thatcham security status. However, an immobiliser is.
Just like Category 1 systems, a Category 2 device has to isolate at least two circuits or systems – or one vehicle control unit that’s required for the car to run properly. Again, it has to be passively set.
This Category is achieved if upgrade work is carried out on a Category 2 vehicle.
As long as the car has Category 2 security status, adding an alarm with the above facets from Category 1, the car can be upgraded to group 2/1, potentially lowering your vehicle insurance premiums.
Unlike the Categories above, Category 3 immobilisation devices are mechanical, not electric. This means they are physical devices that disrupt how a car operates.
They are generally easy to set and unset, with the rules stating that they have to isolate a minimum of one operating system required for vehicle use. They can be permanently or temporarily installed. Category 3 devices include steering wheel and gear lever locks.
Most modern cars fitted with alloy wheels benefit from locking wheel nuts. These make it harder for thieves to steal your wheels, as a special key is needed to remove one of the nuts.
They actually count as a Category 4 Thatcham-approved device, which have to be reliable and durable, have a secure key replacement procedure, feature a traceable product and provide resistance to attack.
These systems can track the whereabouts of a stolen vehicle, but also have the ability to immobilise the car remotely by capping certain engine functions so the car can be shut down. This function is not permitted on Category 6 or 7 systems, though.
Trackers with this function can track a vehicle, but don’t permit it to be remotely shut down.
Similar to the above, immobilisation of the stolen car from a different location is not allowed.
These can include aftermarket alarms and immobilisers, vehicle marking features, data recorders, vehicle ID and signalling systems and improved door locks that have not been approved by Thatcham.