In October 2016, Kim Kardashian was held at gunpoint in her Paris hotel room. Her personal security team had gone with her sister to a nightclub elsewhere in the city. That left her alone when armed intruders, posing as police officers, forced their way in at around 3am.
No monitored alarm covered the entry point that night. There was no signal to trip, no monitoring centre watching and nobody positioned to respond. The story became famous for what was missing, not for what went wrong with a system.
What matters isn't whether an alarm would have helped that night. It's what actually happens, step by step, when a monitored alarm system does its job.
Most people picture someone watching a bank of screens, waiting for something to happen. That's not how it works.
In short, alarm monitoring works like this: the moment a sensor trips, your control panel sends a signal to a monitoring centre staffed around the clock, where a trained operator verifies it's genuine before deciding whether to contact your keyholders, the police or both.
Alarm monitoring is a chain of specific, timed actions. Each link runs on its own technology and its own British Standard, from how the signal travels to how a confirmed alarm gets verified.
Burglary hasn't gone away, even as the wider trend improves. Police-recorded burglary fell 6% to 253,912 offences in the year ending December 2024. That's still 71% lower than in the year ending March 2003 (ONS, Crime in England and Wales, 2024). Fewer incidents still means real incidents. What matters is what your system does in the seconds after one starts.
When a sensor trips, your control panel sends a coded signal immediately.
That signal normally travels over more than one path. A broadband connection, backed up by a SIM-based signal, is typical. If one path fails, the other carries the alarm through regardless. This dual-path principle sits behind BS EN 50136-1:2012+A1:2018, the European standard covering alarm transmission systems.
The signal lands at an Alarm Receiving Centre or ARC. This is a facility staffed around the clock, built to receive these signals and act on them. That's what ARC monitoring means in practice: continuous signal reception, verification and escalation, carried out at a facility built and audited for the job rather than a generic call centre. How an ARC handles a signal once it lands is itself covered by a separate standard, BS 9518:2021. Our commercial alarm systems monitor through Southern Monitoring. UK Alarm Receiving Centres operate to BS EN 50518:2019+A1:2023, the standard governing how monitoring centres themselves must run.
An ARC operative doesn't pass every signal straight to the police. They confirm it's genuine first.
That step exists for a reason. False activations are common enough that verification protocols exist across the industry, so genuine alarms don't get lost among them.
UK confirmation is governed by BS 8243:2021, the standard defining how systems generate a "confirmed alarm condition." It recognises three ways to confirm a signal is real: two separate detectors triggering within a set window, an operator listening in or a camera showing what's actually happening. NSI-approved companies have designed to this standard since 30 June 2022.
Confirmation isn't optional for most installations, either. New systems have had to conform to PD 6662:2017 since 1 June 2019, the umbrella scheme that calls up BS 8243:2021 for confirmed alarm generation. Under BS EN 50131-1's separate Grade 1-4 equipment classification (a different scale entirely from the NPCC police-response tiers below), only the highest-grade systems are exempt from the confirmation requirement altogether.
Standards like this work. Registered Intruder Alarms grew from 796,078 in 1995 to 1,493,706 by 2020. Over that same period, false alarm calls to police fell by more than 1.1 million (Secured by Design, Alarm Standard Technical Guide, 2022). More monitored systems, fewer wasted call-outs.
Once an alarm is confirmed, the ARC works through your keyholder list.
Current policy requires at least two keyholders per premises. Each must be able to attend within 20 minutes of being contacted (NPCC, Police Requirements for Security Systems, 2022/23). If your listed contacts can't be reached or can't arrive fast enough, that's where a professional key holding service earns its place, under BS 7984-1:2016, the key holding and response services standard.
Even when every step above happens correctly, police attendance still depends on two things: a valid Unique Reference Number (URN) and a confirmed signal.
Current NPCC policy recognises only two response levels. Level 1 is immediate response. But the NPCC's own wording is blunt: attendance is "ultimately determined by demand, priorities and resources" and "cannot be guaranteed." Level 3 is withdrawn: keyholder response only, with no police attendance at all.
A system drops to Level 3 after three false alarms within a rolling 12-month period, for a minimum of 14 days. Reinstating Level 1 status requires 90 days clear of confirmed false alarms (NPCC, 2022/23).
This is why Step Two matters so much. A poorly configured system racks up false alarms and loses Level 1 status. That leaves no police response - exactly when a genuine break-in happens.
"In responding to alarms, speed is of the essence - it can be a matter of life and death," says Richard Jenkins, CEO of NSI. Every step in this chain exists to protect that speed.
Kim Kardashian's ordeal shows what happens with no monitoring layer at all. The Hatton Garden Safe Deposit burglary shows something different and arguably more instructive.
Overnight on 2-3 April 2015, thieves broke into the vault beneath Hatton Garden Safe Deposit in London. Southern Monitoring Alarm Company detected the intrusion and confirmed it as genuine. (This is named here as an illustrative industry example, not as a historical Blake client.) The call reached the Metropolitan Police's Central Communications Command at 00:21 on 3 April 2015.
No officers attended. The call was graded in a way that meant it never reached a patrol.
The thieves returned for one further night, uninterrupted. Police later estimated around £14m had been taken. Only £4.3m was ever recovered.
Metropolitan Police Commander Peter Spindler later apologised publicly: "Our normal procedures would have resulted in police attending the scene and we apologise that this did not happen."
Detection worked. Confirmation worked. The call worked. The failure sat in the next link - grading and dispatch. That's exactly why understanding the whole chain matters, not just the first two steps.
We built our monitored alarm systems around this whole chain, not just the sensor at the end of it.
Every system we design is built to NSI and SSAIB standards, monitored 24/7 through Southern Monitoring and configured with zonal protection specific to your premises. Unlike Kardashian's hotel room, that means you can secure part of a building while still moving freely through the rest. It also means the chain above runs the same way at 3pm or 3am. A genuine trip still reaches the ARC and gets verified. It still moves to your keyholders. And if your Level 1 status holds, it still reaches the police too - whether or not you're the one who noticed first.
We hold both NSI Gold and SSAIB certification, achieved through two separate audit regimes: SSAIB since 2002, NSI Gold since 2005. Between them, two independent bodies check our processes on Intruder Alarm Systems, not just one.
Each engineer specialises in their discipline. Our surveyors match the right engineer to your system before installation begins.
"On the 21st December of last year, I had a complete breakdown of the school's intruder alarm... Within hours I had two engineers on site... I am extremely satisfied with all of the disciplines provided by Blakes and I am happy to continue to use Blakes for many years to come."
Leonard Levey, Site Manager, St Anne Line Junior Catholic School
That's the response we want every client to get, whatever the size of the job. We're big enough to cope, small enough to care.
That's family-run from our Southend HQ. And if we're not qualified to provide a service, we won't offer it.
When a sensor trips, your control panel sends a coded signal immediately over two separate paths, typically a broadband connection backed up by a SIM-based route, so if one fails the other still carries the alarm through. This dual-path principle is set out in BS EN 50136-1:2012+A1:2018, the European standard covering alarm transmission systems. The signal arrives at an Alarm Receiving Centre or ARC, a facility staffed around the clock and built to receive and act on these signals. Blake's commercial alarm systems are monitored through Southern Monitoring. UK Alarm Receiving Centres operate to BS EN 50518:2019+A1:2023, the standard governing how monitoring centres themselves must run.
Not automatically. Police attendance depends on two things: a valid Unique Reference Number and a confirmed signal. Current NPCC policy recognises only two response levels: Level 1, immediate response and Level 3, withdrawn, where only keyholders respond and no officers attend at all. Even at Level 1, the NPCC's own wording is blunt: attendance is "ultimately determined by demand, priorities and resources" and "cannot be guaranteed." A system drops to Level 3 after three false alarms within a rolling 12-month period, for a minimum of 14 days and needs 90 days clear of confirmed false alarms before Level 1 status is reinstated. That is why accurate verification at the ARC stage matters so much.
Before an ARC operative passes a signal to police, they confirm it is genuine using methods set out in BS 8243:2021, the standard that defines a "confirmed alarm condition." That might mean two separate detectors triggering within a set window, an operator listening in or a camera showing what's actually happening. NSI-approved companies have designed to this standard since 30 June 2022. Verification matters because unconfirmed signals are unreliable. UK registered Intruder Alarms grew from 796,078 in 1995 to 1,493,706 by 2020, while false alarm calls to police fell by more than 1.1 million over the same period.
Once an alarm is confirmed, the ARC works through your keyholder list. Current policy requires at least two keyholders per premises and each must be able to attend within 20 minutes of being contacted, under the NPCC's Police Requirements for Security Systems 2022/23. If your listed contacts cannot be reached or cannot get there fast enough, that gap is exactly where a professional key holding service earns its place, providing a dedicated responder so the chain does not stall at this step. Without a reliable keyholder response, a confirmed alarm can go unattended even when detection, transmission and verification have all worked correctly upstream.
Yes. The Hatton Garden Safe Deposit burglary in April 2015 shows this. Southern Monitoring Alarm Company detected the intrusion, confirmed it as genuine and the call reached the Metropolitan Police's Central Communications Command at 00:21 on 3 April 2015. This is cited as an illustrative industry example, not a historical Blake client. No officers attended, because the call was graded in a way that meant it never reached a patrol. Detection worked, confirmation worked, the call worked; the failure sat in grading and dispatch, the link after the ones most people assume carry the risk. Thieves returned for one further night and police later estimated around £14m had been taken, with only £4.3m ever recovered.
Both are third-party certification schemes covering Intruder Alarm Systems, but they are two separate audit regimes run by two independent bodies, not one scheme with two names. Blake holds SSAIB certification since 2002 and NSI Gold since 2005 and the two cover overlapping ground, meaning our processes are checked independently by both bodies rather than relying on a single assessor's judgement. This dual certification sits alongside 24/7 monitoring through Southern Monitoring, an ARC operating to the BS EN 50518:2019+A1:2023 standard and together these standards underpin every stage of the monitoring chain, from signal transmission through to police response eligibility.
If your current alarm provider can't explain what happens after it goes off, that's worth asking about now, not after an incident.
We design, install and monitor commercial alarm systems across Essex, London and the surrounding counties, matched to 24/7 ARC monitoring through Southern Monitoring.
Call us on 01702 447800 or email info@blakefire-security.co.uk to arrange a survey. Or visit our contact page to get started.
