Two questions come up in almost every enquiry we get across London: is this actually legal, and will it cause problems with my manufacturer warranty. Here's the straightforward answer to both.
Is it legal?
Yes. Fitting a Thatcham-approved hidden immobiliser is completely legal in the UK and is, in fact, actively encouraged by insurers as a recognised anti-theft measure. There's no restriction on connecting an approved aftermarket security device to your vehicle's CAN BUS system, provided it's fitted correctly and doesn't interfere with the car's core safety systems — which is exactly what Thatcham approval certifies in the first place.
Does it void my manufacturer warranty?
Under UK and EU consumer protection law (the block exemption regulation), a manufacturer cannot void your entire warranty simply because an aftermarket part has been fitted. They can only refuse a warranty claim if they can demonstrate the specific fault was caused directly by that modification — and a professionally fitted, Thatcham-approved immobiliser fitted by following the manufacturer's own CAN BUS specification essentially never causes this kind of issue.
In practice, we've never had a London customer report a warranty claim being refused because of a Scorpion X fitting.
What makes a fitting "safe" for your warranty
- Connecting to the correct CAN BUS point using the manufacturer's documented wiring, not a bodged splice
- Using a genuinely Thatcham-approved device, not a grey-market clone
- A fitter who tests every affected system afterwards — lights, locking, dash warnings — before handing the car back
- Full documentation of what was fitted and where, in case it's ever needed for a warranty conversation
What actually can cause problems
The risk isn't the immobiliser category itself — it's cheap, uncertified units fitted by someone cutting corners on wiring. A badly spliced connection into the CAN BUS can genuinely cause electrical faults, which is the scenario manufacturers are (rightly) cautious about. That's the entire reason Thatcham approval and professional fitting exist as a standard in the first place — especially relevant in London, where premium and prestige vehicles under warranty make up a large share of our bookings.
Fitted Properly, Documented Properly
Thatcham approved Scorpion X, fully certified, anywhere in London.
Get My Free Quote →Frequently Asked Questions
Do I need to tell my insurer I've had one fitted?
Yes — and you'll want to, since it's usually what earns you the premium discount in the first place. We provide a fitting certificate specifically for this.
Will a dealership technician be able to tell it's fitted?
Only if they're specifically looking for CAN BUS modifications and know what to check for. It won't show up as a fault or trigger any dashboard warning light.
Can I have it removed if I sell the car?
Yes, we can remove it or hand over the service PIN and documentation so a new owner can take over the existing unit instead.