If your business has an intruder alarm, the most important question is not whether it makes a noise when triggered — it is whether anyone with the authority to act will respond when it does.

Across Cardiff, Penarth, Barry, and the wider Vale of Glamorgan, we see this regularly: businesses that believe they have a monitored, police-response alarm, only to discover that their system was never registered, does not meet the required standard, or was installed by a company that lost its certification years ago. When a break-in happens, the alarm sounds — and nobody comes.

In the UK, police response to intruder alarms is not automatic. It is conditional. The police will only respond to an alarm activation if the system meets specific standards, is installed by an approved company, and is registered with an Alarm Receiving Centre (ARC) that holds the appropriate accreditation. A system that does not meet these requirements is, in practical terms, a deterrent only — and a limited one at that.

This guide explains the standards that govern police-response intruder alarms in the UK, what they require, and why the system MH Fire & Security install across Cardiff, Penarth, Barry, Newport, Bridgend, and South Wales — built on Ajax technology — delivers full compliance alongside one of the most capable alarm platforms available today.

---

The Standards That Matter: PD 6662:2017 and BS 8243:2020

PD 6662:2017 — The Framework for Alarm Systems

PD 6662:2017 is the British Standard published document that sets out the scheme for applying European standards to intruder and hold-up alarm systems in the UK. It provides the framework within which alarm systems must be designed, installed, and maintained to qualify for police response.

PD 6662 references the European standard BS EN 50131, which defines the performance requirements for intruder alarm systems across four security grades:

• Grade 1 — low risk; basic systems for domestic use
• Grade 2 — low to medium risk; most residential and small commercial applications
• Grade 3 — medium to high risk; commercial premises, businesses with significant assets, premises requiring police response
• Grade 4 — high risk; high-security installations

For most businesses seeking police response, Grade 3 is the relevant benchmark. A Grade 3 system must meet significantly more demanding requirements than a standard domestic alarm — including tamper detection, anti-substitution measures, secure communication paths, and resistance to jamming and interference.

BS 8243:2020 — The Standard for Police Response

BS 8243:2020 is the British Standard that governs the installation and configuration of intruder alarm systems specifically intended to receive a police response. It sets out the conditions under which the police will attend an alarm activation, including:

• The system must be installed by a company certificated by an UKAS-accredited certification body (such as SSAIB)
• The system must be monitored by an ARC that holds the appropriate NSI or SSAIB accreditation
• The system must use confirmed alarm protocols — meaning the police will only be dispatched following confirmation that a genuine intrusion has occurred, not on a single unverified trigger
• The system must be registered with the relevant police force

The confirmed alarm requirement is critical. Under BS 8243:2020, a single activation is not sufficient to generate a police response. Confirmation can be achieved through sequential detection (two independent detectors triggering within a set time window), audio or visual verification, or a combination of methods. This dramatically reduces false alarm rates — which is why the police introduced the confirmed alarm requirement in the first place.

---

Why Compliance Matters for Your Insurance

Most commercial property and liability insurers specify minimum security standards as a condition of cover. For businesses holding significant stock, cash, or equipment — whether you are a retailer on Cardiff's high street, a trade business in Barry, a professional services firm in Penarth, or a warehouse operation in Newport — insurers will typically require:

• An intruder alarm installed to a recognised standard (PD 6662 / BS EN 50131)
• Installation by an SSAIB or NSI certificated company
• Monitoring by an accredited ARC
• In many cases, a Grade 3 system specifically

A system that does not meet these requirements may not satisfy your policy conditions. In the event of a break-in, your insurer may reduce or refuse a claim on the grounds that the security provision was inadequate. The cost of a compliant, professionally installed system is almost always a fraction of the potential uninsured loss.

Beyond the policy conditions, a fully compliant system with documented installation and maintenance records gives you a strong position in any claim — demonstrating that you took your security obligations seriously and invested in a system that met the required standard.

---

The Ajax System: Grade 3 Wireless Technology

MH Fire & Security install intruder alarm systems built on the Ajax platform — one of the most advanced wireless security systems available, and one of the few wireless platforms capable of achieving full Grade 3 compliance under BS EN 50131.

Ajax Systems protect over 4.5 million people worldwide, and their technology is trusted by professional installers and monitoring companies across Europe and beyond. Here is what makes the Ajax platform the right choice for a compliant commercial installation.

Wireless Grade 3 Compliance

Ajax devices are certified to BS EN 50131 Grade 3, meaning they meet the most demanding requirements for commercial intruder alarm systems. This includes:

• Anti-jamming protection — Ajax devices detect radio frequency jamming attempts and immediately alert the system. Unlike lower-grade wireless systems, a Grade 3 Ajax installation cannot be silenced by a cheap RF jammer
• Anti-masking — Ajax motion detectors detect attempts to cover or obstruct them and raise an alert before an intruder can neutralise the sensor
• Tamper detection — every Ajax device has a built-in tamper switch that triggers an alert if the device is opened, removed from its mount, or interfered with
• Encrypted communication — all communication between Ajax devices and the hub uses 128-bit AES encryption, preventing interception or spoofing

Dual-Path Communication

A Grade 3 system under PD 6662 requires resilient communication between the alarm panel and the ARC. Ajax hubs support dual-path signalling — simultaneously communicating over Ethernet and mobile data (GSM/LTE). If one path is disrupted, the other maintains the connection to the monitoring centre without interruption. This meets the communication requirements for police-response systems and ensures that a cut broadband line does not silence your alarm.

The Ajax Security System App

Every Ajax installation comes with access to the Ajax Security System app, available on iOS and Android. The app gives you:

• Real-time notifications — instant push alerts to your phone when the alarm is triggered, a detector is activated, or a tamper event occurs
• Remote arm and disarm — arm or disarm your system from anywhere in the world, directly from your phone
• System status at a glance — see the status of every detector, keypad, and device on your system in real time
• Event history — a full log of every system event, with timestamps, so you always know exactly what happened and when
• Multiple users — add staff members, managers, or keyholders with individual access levels and permissions

This is not a bolt-on feature — it is built into the Ajax platform and works seamlessly alongside your ARC monitoring. You receive the same notification your monitoring centre receives, simultaneously.

Scalable and Expandable

Ajax systems are modular. A system installed today can be expanded as your business grows — adding detectors, keypads, sirens, CCTV cameras, or access control devices without replacing the core infrastructure. This makes Ajax a long-term investment rather than a fixed installation that becomes obsolete as your requirements change.

---

What Police Response Actually Means

When your system is registered for police response and a confirmed alarm is generated, the ARC contacts the police with a URN (Unique Reference Number) — the identifier that tells the police your system is compliant and registered. Without a URN, the police will not attend.

The police response is graded:

• Level 1 response — immediate response, typically for confirmed activations with evidence of intrusion
• Level 2 response — scheduled response, for activations that meet the confirmed alarm criteria but where the risk assessment suggests a lower urgency

For businesses in Cardiff, Penarth, Barry, and the Vale of Glamorgan, the relevant force is South Wales Police. Response timescales and grading are subject to South Wales Police's alarm policy, and your ARC will advise on the specific arrangements for your premises and area.

It is worth noting that police response is a privilege, not a right — and it can be withdrawn. Excessive false alarms from a non-compliant or poorly maintained system can result in the police removing your URN, leaving you without a response capability. A properly installed and maintained Grade 3 system, with confirmed alarm protocols in place, keeps false alarm rates low and your URN secure.

---

The Role of the SSAIB Certificated Installer

The police will only register a system for response if it has been installed by a company certificated by an UKAS-accredited body. MH Fire & Security are SSAIB certificated, which means:

• Our installations are audited against PD 6662:2017 and BS EN 50131 Grade 3
• We are authorised to register systems for police response on your behalf
• Our work is subject to ongoing third-party assessment — not just a one-time check
• We can provide the documentation your insurer requires to confirm compliance

Choosing an uncertificated installer — however competent they may appear — means your system cannot be registered for police response and will not satisfy the conditions of most commercial insurance policies. The certification is not a formality; it is the gateway to the protections that make a professional alarm system worthwhile.

---

What a Compliant Installation Looks Like in Practice

When MH Fire & Security install a PD 6662:2017 and BS 8243:2020 compliant system for your business, the process includes:

1. Site survey — assessing your premises, identifying risks, and specifying the appropriate Grade 3 devices and coverage
2. System design — producing a compliant system design that meets the requirements of PD 6662 and your insurer's specification
3. Professional installation — fitting Ajax devices to the required standard, with full tamper protection and secure cable management
4. ARC registration — connecting your system to an accredited monitoring centre and registering for police response with your local force
5. Commissioning and handover — testing every device, setting up the Ajax app for your keyholders, and providing full documentation
6. Ongoing maintenance — annual service visits to keep your system compliant and your URN active

---

Is Your Current System Compliant?

Many businesses have intruder alarms that were installed years ago by companies that are no longer certificated, to standards that have since been superseded, or without ARC monitoring. If you are not certain whether your system qualifies for police response, the answer is almost certainly that it does not.

MH Fire & Security can carry out a compliance assessment of your existing system and advise on whether it can be upgraded or whether a new installation is the right approach. In many cases, an Ajax system can be installed alongside or in place of an existing system with minimal disruption to your business.

---

Serving Businesses Across Cardiff, Penarth, Barry & South Wales

MH Fire & Security are based in Penarth and install PD 6662:2017 and BS 8243:2020 compliant intruder alarm systems for businesses throughout the region. Our installation and maintenance coverage includes:

• Cardiff — city centre, Canton, Roath, Pontprennau, Cardiff Bay, Llandaff, Whitchurch, and all surrounding areas
• Penarth — our home town; we serve businesses across Penarth, Sully, Dinas Powys, and the surrounding Vale communities
• Barry — Barry town centre, Barry Dock, Rhoose, Cadoxton, and the wider Vale of Glamorgan
• Newport — Newport city centre, Cwmbran, Caerleon, and surrounding Gwent areas
• Bridgend — Bridgend town, Pencoed, Porthcawl, and the surrounding borough
• Pontypridd & the Valleys — Pontypridd, Caerphilly, Rhondda, and surrounding areas
• Vale of Glamorgan — Cowbridge, Llantwit Major, St Athan, Rhoose, and all Vale communities

Whether you are a small independent retailer in Penarth, a multi-site business across Cardiff, or a warehouse operation in the Vale of Glamorgan, we will survey your premises, design a compliant system, and handle everything from installation through to ARC registration and ongoing maintenance.

If you would like to discuss a compliant intruder alarm installation for your business, get in touch for a no-obligation survey. We cover the whole of South Wales and are happy to advise on the right system for your premises and risk level.

• Intruder alarm installation and maintenance
• CCTV installation and maintenance
• Access control systems
• Why choose an SSAIB certificated company