Thatcham security explained: alarms, immobilisers and trackers

Key Takeaways:

• Thatcham categories set the standard for vehicle security.
• The key security categories are explained.
• Updated standards reflect modern theft threats.
• Choosing the right security can impact insurance and theft risk.

When it comes to protecting your vehicle from theft, not all security devices are created equally which is why for drivers in the UK, Thatcham Research sets the standard for vehicle security.

It’s an independent organisation which categorises alarms, immobilisers and trackers to help consumers, and insurers, understand their effectiveness.

But what do terms like ‘Thatcham Category 1’ or ‘Category S5’ mean?

In this guide, the vehicle security experts at Ghost Installations will break down Thatcham’s security categories, explain why they matter and show how choosing Thatcham-approved vehicle trackers, or immobilisers, can enhance your car’s safety and potentially lower your insurance premiums.

What is Thatcham Research?

Thatcham Research is a UK-based organisation that has been a cornerstone of vehicle safety and security since the 1960s.

When car theft rates began rising in the 1990s, Thatcham began testing and certifying vehicle security products, setting benchmarks that manufacturers and aftermarket providers must meet.

A Thatcham-approved device signals quality and reliability, having undergone rigorous evaluation to ensure it effectively deters or prevents theft.

This credibility makes Thatcham ratings a key factor for both car owners and insurers.

Overview of Thatcham security categories

Thatcham’s security categories classify vehicle security devices, such as alarms, immobilisers and trackers, based on their effectiveness.

These categories, often numbered or prefixed with an ‘S’ for trackers, reflect specific standards and features.

Since 2019, Thatcham has updated its classification system to combat modern vehicle theft methods, but the core idea remains: a Thatcham rating assures quality.

Insurers frequently ask whether a vehicle has a Thatcham-approved device, as this can influence eligibility for coverage or reduce premiums by demonstrating a lower theft risk.

Thatcham Category 1: The gold standard for alarms and immobilisers

Thatcham Category 1 represents the highest level of vehicle security for combined alarm and immobiliser systems, that is for pre-2019 standards.

A Category 1 device includes both an electronic alarm that detects intrusion, for example, a door being opened or glass broken, and an immobiliser that prevents the engine from starting without the correct key or transponder.

Many high-end vehicles come equipped with Category 1 systems as standard, offering robust protection against theft.

For insurers, a Category 1 rating is a strong indicator of comprehensive security, often satisfying their strictest requirements.

Thatcham Category 2: Immobiliser-only protection

Category 2 devices focus solely on electronic immobilisers, which prevent a vehicle from starting without the proper key or transponder being present.

Unlike Category 1, these systems don’t include an alarm, so they won’t alert you to a break-in but will stop a thief from driving away.

Category 2 is common in older, or nonpremium, vehicles.

For those looking to upgrade, a Category 2-1 solution exists: adding a Thatcham-approved alarm to a Category 2 immobiliser effectively brings the vehicle up to Category 1 standards, enhancing security and potentially improving insurance terms.

Thatcham Category 3 and 4: Mechanical security devices

Thatcham also certifies mechanical security devices, though these are less prominent on today’s insurance forms, which prioritise electronic systems.

Category 3 covers mechanical immobilisers, such as steering wheel locks or gear locks, which physically prevent a vehicle from being driven.

Category 4 includes wheel-locking devices, like locking wheel nuts, which deter wheel theft.

While these devices add valuable layers of protection, they’re often supplementary to electronic systems.

A steering wheel lock, for instance, is a simple yet effective deterrent, even if it doesn’t carry the same insurance weight as a Category 1 or 2 device.

Thatcham Category S5: Top-tier vehicle tracking

For stolen vehicle recovery Thatcham Category S5, formerly Category 5, is the best.

Category S5 trackers are advanced systems with features like Automatic Driver Recognition (ADR), where the driver carries a tag, and the vehicle alerts a monitoring centre if moved without it.

S5 trackers offer 24/7 monitoring, advanced jamming detection and sometimes remote immobilisation.

These systems are often required by insurers for high-value vehicles due to their effectiveness in recovering stolen cars.

The S5 designation replaced the older Category 5 post-2019 but maintains its high-security focus.

Thatcham Category S7: Standard vehicle tracking

Category S7 trackers provide a more accessible level of stolen vehicle recovery.

Unlike S5, S7 trackers don’t require ADR tags, but they still offer robust tracking and theft alerts making them effective for recovering stolen vehicles.

While highly reliable, S7 systems are a step below S5 in terms of features, so some insurers may only give partial credit for S7 or insist on S5, for high-risk or high-value cars.

Prior to 2019, similar systems were classified as Category 6 or 7, with Category 7 often referring to simpler, sometimes battery-powered, trackers.

Other Thatcham categories

Some manufacturers use terms like ‘S5+’ to market trackers with added features, such as immobilisation on top of S5 standards.

Older categories, like Category 5 for trackers using VHF signals, may still appear in discussions about legacy systems, but they’re less relevant today.

For most consumers, focusing on Categories 1, 2, S5 and S7 covers the essentials needed for insurance and security decisions.

Why Thatcham categories matter to you

Understanding Thatcham categories empowers you to make informed choices about vehicle security and insurance.

A Thatcham Category 1 device, for instance, assures insurers that your car has top-tier alarm and immobiliser protection, potentially lowering premiums.

When selecting a tracker, knowing the difference between Category S5 and S7 helps you meet your insurer’s requirements without overspending.

Choosing Thatcham-approved devices ensures you’re investing in vetted, effective products, unlike many cheap and unverified gadgets that may not be recognised by insurers or provide adequate protection.

Ghost Installations and Thatcham devices

At Ghost Installations, we specialise in Thatcham-approved solutions tailored to your vehicle’s needs.

Our Category S5 and S7 trackers meet the highest industry standards for stolen vehicle recovery, while our alarm and immobiliser installations meet with Category 1 and 2 requirements.

The Autowatch Ghost II immobiliser, for example, is a cutting-edge aftermarket immobiliser that, while not assigned a specific Thatcham category, is widely recognised by insurers for its unique anti-theft technology.

We ensure every installation meets or exceeds insurer expectations, giving you peace of mind and enhanced security.

Understanding Thatcham security categories

Thatcham security categories aren’t just technical jargon; they’re a roadmap to better vehicle protection and smarter insurance decisions.

By understanding the differences between Category 1 alarms, Category 2 immobilisers and S5 or S7 trackers, you can choose the right security for your car.

Check your vehicle’s current security setup: does it have a Category 1 system, or could it benefit from an upgrade?

If your insurer requires a tracker, consider whether an S5 or S7 best suits your needs.

For expert advice or to explore Thatcham-approved solutions, contact Ghost Installations. We’ll help you navigate these categories and recommend the perfect security setup for your vehicle.