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Car Insurance Immobiliser Discount – can it reduce your premium?
The relationship between aftermarket immobilisers and UK car insurance is nuanced. Here’s what insurers actually say – and how to have the conversation that might save you money.
The Car Insurance Immobiliser Discount question has a simple answer: sometimes yes, it depends on the insurer and the product. The complete answer requires understanding Thatcham categories, insurer policy requirements, and how to present the modification correctly to your provider.
What insurers look for with a Car Insurance Immobiliser Discount
Most UK car insurers use the Thatcham Research classification system to evaluate security devices. Thatcham categories run from Category 1 (full alarm and immobiliser) through to Category 7 (stolen vehicle tracking). A Thatcham-approved product has been through Thatcham’s testing process and been assigned a category number.
Insurers respond differently to Thatcham vs non-Thatcham aftermarket security. Some offer an automatic Car Insurance Immobiliser Discount for any Thatcham-approved product. Others require a specific category (Category 5 or 6 for tracking). Others treat any professionally installed immobiliser positively, whether Thatcham-approved or not.
How installation works and what is included
Getting a Car Insurance Immobiliser Discount starts with having the right device professionally fitted. LockCar supplies and installs immobilisers across the UK through approved mobile installers. Here is how the process works from start to finish.
Step 1 – Choose your product: Decide which immobiliser suits your vehicle and your insurer’s requirement. The LockCar i226 is £79 for the unit, the IC3ST is £139, the ONE is £199, and the One Plus is £259. Fitted prices start from £300, depending on the product and your vehicle.
Step 2 – Confirm your insurer’s requirement: If your insurer has stated a specific Thatcham category or product type, tell us before booking. We can provide a product specification sheet to support the conversation.
Step 3 – Mobile installation: An approved installer comes to your home or workplace. Installation typically takes 60 to 90 minutes depending on the product and vehicle. The relay break is fitted in the start circuit, downstream of the factory immobiliser, the OBD port, and the CAN bus.
Step 4 – Documentation and handover: You receive full installation documentation including the device serial number, installation date, vehicle registration, and a technical description of the relay break mechanism. This is what you present to your insurer when applying for a Car Insurance Immobiliser Discount.
What is included: The immobiliser unit, all wiring and connectors specific to your vehicle, professional mobile installation, full testing with you present, and the documentation pack for your insurer. No hidden extras within our covered areas.
The conversation to have with your insurer
Ask: “Does a professionally fitted relay immobiliser reduce my premium?”
Be specific. “Relay immobiliser” may trigger a different response than “immobiliser.” Ask whether the method of fitting – relay vs CAN bus – matters to them.
Ask: “Do you require Thatcham approval specifically?”
Some insurers do, some don’t. If they require a specific Thatcham category, ask which one and whether any products you’re considering qualify.
Disclose the fitting – always
Tell your insurer when you fit any aftermarket security device. A professionally installed immobiliser is a beneficial modification – but it is still a modification that your insurer should know about.
When insurers mandate specific products for a Car Insurance Immobiliser Discount
For Range Rovers, BMW X5/X6, and similar high-theft vehicles, some insurers have begun requiring Thatcham-approved security as a condition of cover – not just offering a Car Insurance Immobiliser Discount for it. If your renewal states that approved security is required, do not fit a non-Thatcham product without confirming with your insurer that it satisfies their requirement. Victor can provide a product specification sheet to support this conversation.
If your insurer requires a specific product, contact us before booking so we can match the right LockCar immobiliser to their requirement. Getting this right protects both your cover and any Car Insurance Immobiliser Discount you are entitled to claim.
Areas covered for Car Insurance Immobiliser Discount installations
LockCar mobile installation covers the entire UK. Approved installers fit immobilisers in England, Scotland, and Wales, with same-day and next-day appointments available in most areas. Whether you are in a major city or a rural location, we can arrange a mobile visit at your home or workplace.
For more detail on choosing and fitting a device, see our Car Immobiliser Guide 2026, our Complete Car Immobiliser Buyer’s Guide for UK Drivers, and our Best Dash Cam for Car Insurance Claims UK 2026 page. Our main Car Immobiliser page explains the full LockCar range.
Frequently asked questions about Car Insurance Immobiliser Discount
Does fitting an immobiliser reduce my car insurance?
Sometimes. Some insurers offer a Car Insurance Immobiliser Discount for Thatcham-approved products, others require a specific category, and others treat any professionally installed immobiliser positively. The only way to know is to ask your insurer directly.
Do I need to tell my insurer I have fitted an immobiliser?
Yes. Always disclose aftermarket security to your insurer. A professionally installed immobiliser is a beneficial modification, but it is still a modification that your insurer should know about.
What documentation do I need for a Car Insurance Immobiliser Discount?
Every LockCar installation comes with a full certificate including device serial number, installation date, vehicle registration, and a technical description of the relay break mechanism. This is what you present to your insurer.
What if my insurer requires Thatcham approval specifically?
Tell us before booking. We can provide a product specification sheet to support the conversation with your insurer, and confirm which LockCar product matches their stated requirement.
How much does a professionally fitted immobiliser cost?
The LockCar i226 is £79 for the unit, the IC3ST is £139, the ONE is £199, and the One Plus is £259. Fitted prices start from £300, depending on the product and your vehicle.
How long does installation take?
Installation typically takes 60 to 90 minutes depending on the product and vehicle. Our mobile installer comes to your home or workplace and tests the system with you before leaving.
Not sure which product your insurer will accept?
WhatsApp Victor with your insurer’s stated requirement. He’ll tell you directly which LockCar product to ask about – and provide any documentation your insurer needs.
Ask the insurance question → Browse productsfrom £300 fitted
