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Dummy alarm vs real alarm

Updated: 20.10.2026

You are looking at a plastic bell box of about £20 and wondering whether it will satisfy an insurer, or whether the police would treat the lens as a live system. A dummy alarm vs real alarm is that split: a sign on the wall, or a system that can detect, sound, or send a signal. Prices and the six listings sit on the [dummy alarm system comparison](/hub/burglar-protection/dummy-alarm-system). Those amazon.co.uk listings and public UK sources were read on 19 October 2026. This is not a lab test. A qualifying purchase can earn us a commission at no extra cost to you.

You are looking at a plastic bell box of about £20 and wondering whether it will satisfy an insurer, or whether the police would treat the lens as a live system.

Our top picks

Yale Yale AC-DBX dummy siren

Best overall

Yale Yale AC-DBX dummy siren
9.1/10about £22.03
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Nedis Nedis DUMSS20WT dummy siren

Alternative

Nedis Nedis DUMSS20WT dummy siren
8.6/10about £22.74
View offer
QUANAN QUANAN blue dummy alarm box

Best value

QUANAN QUANAN blue dummy alarm box
8.2/10about £19.99
View offer
On this page
  1. 1.What each one can and cannot do
  2. 2.The paperwork a real system can have
  3. 3.What comparison sites say about the premium
  4. 4.When a dummy is still the right object

What each one can and cannot do

A dummy looks like an external siren. It does not detect a person, make the noise of a sounder, or dial anyone. Yale's page for the AC-DBX says the box does not sound or trigger, so the LED is the whole performance. Aviva calls it a cheap deterrent for an opportunistic thief, and a professional may spot a fake. A real alarm notices an event and usually sounds or sends a signal. Sensors, a keypad, or a siren output means you have left this category. The Yale table prints 100 dB beside a visual deterrent. The Nedis table prints 1 dB against a no-sound bullet. The dummy alarm system buying guide is the checklist for that clash.

The paperwork a real system can have

PD 6662:2017 is the NSI update for intruder and hold-up alarms, effective from 1 June 2019, and it sits with BS EN 50131-1. It is the route for a real system, not a label on an empty shell. The practical chain is an approved installer, an alarm receiving centre, and a unique reference number where the insurer wants police response. Compare the Market points readers to NSI or SSAIB for a certificate. Neither body certifies a box you fitted yourself. A flash means a cell is powering a light. ProtectUK does not treat a DIY housing as automatic police attendance. The best dummy alarm system page will not get you that certificate.
Yale Yale AC-DBX dummy siren

Testsieger

Yale Yale AC-DBX dummy siren
9.1/10about £22.03
View offer

What comparison sites say about the premium

MoneySuperMarket says a real alarm may or may not cut the premium, that discounts often need a third-party install, and that dummy alarms do not influence insurance costs. Switchcraft says a dummy will not be acknowledged as a proper security device. Compare the Market says not to use a dummy if the aim is a discount. None of them prints a pound figure. Check your schedule. Telling an insurer you have a burglar alarm, when you only fitted a dummy, is a different risk from owning a decoy. Switchcraft warns that a false statement of that kind can sink a claim. Say you have a visual deterrent, or no alarm, unless a working system is installed. The Nedis sticker is a printed warning, not proof of an alarm receiving centre.

When a dummy is still the right object

Choose a dummy only when the job is a visible sign and you will not describe it to an insurer as an alarm. Aviva's framing is the opportunistic thief, not someone who already knows a dead housing from a live sounder. Choose a real system when you need sound, a notification, or a named certificate. Inside the decoy set the boxes are not interchangeable. The Yale AC-DBX is the top pick for a Yale-shaped housing with cells in the pack, if you ignore the 100 dB row. The blue QUANAN box is the best value only with a disputed weather line and a review of about three weeks of light. Fitting sits on the how to fit a dummy alarm system page. None of that turns the plastic into PD 6662.

Common questions

Is a dummy alarm legal in the UK?
The sources used here do not show a UK law that bans a silent decoy on your own home. What you cannot honestly do is present that housing as a certified or monitored alarm. A false statement to an insurer is a separate problem from owning the plastic.
Will a dummy alarm box reduce my home insurance?
MoneySuperMarket says dummy alarms do not influence insurance costs. Switchcraft says a dummy is not a proper security device. Compare the Market says not to use one for a discount. No pound figure is quoted here. Read your schedule.
Can I tell the insurer I have a burglar alarm if I only fitted a dummy?
No. A dummy does not detect, sound, or signal an alarm receiving centre. Describing it as a burglar alarm is the false statement Switchcraft warns can sink a claim. Say you have a visual deterrent, or no alarm, unless a working system is in place.
Will the police come because the box is on the wall?
Not from the box alone. NSI describes police response through an approved installer, an alarm receiving centre, and a unique reference number, where the insurer requires it. A lens on a dummy is not that chain.
What is PD 6662 in one sentence?
PD 6662:2017 is the NSI scheme document for intruder and hold-up alarms, effective from 1 June 2019, and it sits with BS EN 50131-1. It describes a real system, not a silent housing or a sticker you added yourself.
Does a flashing LED mean the system is set?
No. On these decoys the flash means a cell is powering a light. Yale's UK page says the AC-DBX is not linked to a system. A set real system is armed and can sound or signal. A dark LED usually means flat cells.

Related pages

Dummy alarm system

Best dummy alarm box: match the housing to the job

Dummy alarm box buying guide: six checks on the listing

How to fit a dummy alarm box where passers-by see it

Solar dummy alarm box or a battery housing in the UK

Sources

Public UK sources from the research digest. Listing prices, stars, and review counts are from amazon.co.uk on 19 October 2026.

  1. Yale AC-DBX dummy siren (retrieved 19 October 2026)
  2. Consumer Rights Act 2015, section 11 (retrieved 19 October 2026)
  3. NSI on PD 6662:2017 for intruder and hold-up alarms (retrieved 19 October 2026)
  4. NSI, intruder alarm systems (retrieved 19 October 2026)
  5. Redditch Borough Council home security guide, August 2021 (retrieved 19 October 2026)
  6. CSA Group, ingress protection (IP) testing (retrieved 19 October 2026)
  7. MoneySuperMarket, burglar alarms and home insurance (retrieved 19 October 2026)
  8. Aviva, which alarm system for your home (retrieved 19 October 2026)