Compare subscription alarm systems: what salespeople promise — and what actually happens

Sales representatives almost always emphasise the same things: a low monthly price, “free” installation, a monitoring centre that “calls the police”, anti-jamming and “24/7 protection”. On paper that sounds like an advantage — That is exactly why, during a home visit, we do not start with price but with what happens when things go wrong.

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In practice these are often sales arguments, not real protection. The base package usually detects indoors only, outdoor sirens are missing, and during signal disruption nothing happens on site — while the advertising still sounds reassuring. On this page you compare what salespeople promise with what really happens in the first minute of a break-in.

Signing without knowing what gets installed

Many people sign a subscription before they know exactly what will be installed on their home — and without checking reliability and how it works. Only later do they find out the monitoring centre cannot call the police itself, that outdoor sirens are missing, or that the system does nothing during signal disruption.

What sales representatives rarely mention: no subscription alarm offered on your doorstep is Grade 3 certified under EN 50131 — the highest European level for professional intruder alarm systems. That is not an opinion but an objective quality gap. It is the ultimate proof that the hardware behind the low monthly price is structurally of a lower tier than what a professional installation can deliver.

Overview of independent research (ACM, FACUA, Radar): monitoring centre research.

Four questions you must ask before you sign

Imagine this — and ask every salesperson who wants you to sign a contract these questions.

Imagine this

It is 03:00. Someone walks up your driveway. You are asleep. Your neighbours are asleep. What does your alarm system do — outside, on your phone and at the monitoring centre?

With most standard subscription packages we come across, the answer to three or four points is no.

Question 1

Does a loud siren sound outside?

Not a quiet beep on an indoor panel — but noise your neighbours hear, that drives an intruder away immediately and that also works when nobody is home to respond to an alert.

Typical subscription: often no

Question 2

Do you get an alert straight away?

With many subscriptions the alarm goes to the monitoring centre first — not to your phone. Only then does an operator call you. Don’t answer? Nothing further happens. The question is: do you get an alert on your phone within seconds?

Typical subscription: often delayed or via monitoring centre

Question 3

Does it still work if someone blocks the radio signal?

A jammer is a small signal jamming device that cuts the radio link between sensors and hub. Ask then: does a siren still sound, do you get an alert, or does everything stay silent as if nothing is happening?

Typical subscription: in our test often nothing

Question 4

Is the monitoring centre allowed to call the police itself?

In Spain a private monitoring centre may not call the police without first reaching you — or a contact person you have designated. That is the law, regardless of what a salesperson promises on your doorstep.

Answer: no — regardless of the advertising

The chain you need to understand

Intruder on driveway→Jammer on→System silent→Monitoring centre hears nothing→No siren outside→Walks in undisturbed

Almost every alarm system installed today is wireless. That makes installation easier — but your protection depends on a radio link between sensors, siren and hub. A jammer is a signal jammer designed precisely to cut that link. The problem is not wireless technology itself: it is that many subscription packages do nothing on site during disruption — no siren, no alert, no response where it matters. With almost every standard subscription alarm system we come across, the whole system then stays silent, the monitoring centre hears nothing, while the intruder carries on.

Outdoor detection as an upgrade does not fix that. Even with expensive outdoor sensors: if the wireless signal is not monitored and nothing sounds locally during disruption, you are paying for detection without a real response on site.

Portable signal jammer — Illustration: a portable signal jammer. It switches off the radio link — sensors report nothing, no siren, no alert on your phone, monitoring centre hears nothing.

At a glance

Our installation Typical subscription

Minute 1 of a break-in	Typical subscription	Our installation
Outdoor deterrent	✗ Often no outdoor sirenIn the base package the alarm often only sounds on a quiet indoor panel. Your neighbours hear nothing; an intruder on the driveway notices little.	✓ Loud outdoor sirenNoise that you, your neighbours and the intruder hear immediately. The goal: drive the intruder away on site, before they get inside.
Outdoor detection	✗ Mainly detects indoorsThe standard package usually covers doors and windows indoors. Detection on driveway, garden or terrace is often an expensive upgrade — or missing altogether.	✓ Detection before the house, as standardDuring a home visit we determine where someone is first visible: driveway, garden, terrace. The break-in is signalled before anyone enters your home.
During signal disruption	✗ Often silent during disruptionDuring jamming or signal loss the system often does not notice. No siren, no alert on your phone — as if nothing is happening.	✓ Siren and alert keep workingDuring signal loss or sabotage the outdoor siren still sounds and you get an alert on your phone straight away — no monitoring centre in between.
Certification (EN 50131)	✗ Never Grade 3No subscription alarm that sales representatives offer on your doorstep achieves Grade 3. That highest European level — including protection against sabotage such as jamming — is structurally absent here.	✓ Grade 3 available (AJAX)AJAX is the only brand with a fully wireless Grade 3 system: the highest certification level for professional intruder alarm systems.
Police needed?	✗ Monitoring centre may not call police itselfIn Spain a monitoring centre must reach you or a contact person first. If you do not answer, nothing further can happen — regardless of what the salesperson promises.	✓ In practice almost never neededIn all registered break-in attempts at our customers, the outdoor siren drove the intruder away on site. The problem is resolved before police or monitoring centre come into play.

Comparison based on common subscription packages and our standard installation approach. Individual providers may differ.

The table shows the difference in broad terms. For your home, what matters is what is actually installed — and what happens when things go wrong. You cannot read that from a subscription brochure or a five-minute doorstep pitch.

What a home visit with us involves. That is why we start with a home visit. We do not come to sell a contract, but to assess your property thoroughly — driveway, garden, doors, windows, weak points — and determine how a break-in is prevented, not how you discover one after someone is already inside.

Based on that, we explain how a bespoke AJAX installation protects differently from a standard subscription package: outdoor detection, a siren that sounds even when the connection drops, and a response that still works during signal disruption — with sabotage such as jammers in mind. No monitoring centre that has to wake you first. No scenario where nothing happens if you do not answer the phone.

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More than 3,000 installations since 2019 · Google rating 4.8 · accredited Ajax Systems Partner

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Related: 6 pitfalls with alarm systems — the free series on misleading promises and risks. Or back to all topics.

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