Self-Monitored or Monitored Alarm? Choosing an Ajax System in the UK
A self-monitored alarm sends alerts to your phone and leaves the next step to you. A professionally monitored alarm also reports to a 24-hour alarm receiving centre (ARC), whose operators follow an agreed plan: ring you, ring your keyholders and, where the system qualifies, call the police. Ajax hubs can work either way, or both at once. In the UK, only an approved, police-listed security company can give you police response, and that rule often settles the choice.
Where does the alarm go, and who acts?
With professional monitoring, Ajax says the alarm reaches the monitoring centre and the app at the same moment, so you still see it.
| Self-monitored | Professionally monitored | |
|---|---|---|
| Who is alerted | App users, by push notification, SMS or phone call | The ARC and the app users together |
| Who acts | You, wherever you are | Trained operators, around the clock, using your response plan |
| If you miss the alert | Only the siren, until you check | The operator works down your keyholder list |
| Police response | No automatic response; you call 999 if you see a crime in progress | Possible, if an approved company installs it and the police issue a URN |
| Running cost | No monitoring fee | A monitoring contract, priced by the company |
What do UK police need before they respond to an alarm?
Police response in England, Wales and Northern Ireland follows the National Police Chiefs' Council (NPCC) security systems policy. Police Scotland said in a 2023 freedom of information reply that it runs its own alarm policy.
- Approved companies only: the NPCC's public advice (Appendix H, February 2026) says only companies approved by an independent inspectorate, NSI or SSAIB, and listed with your local force may offer an alarm that gets police response.
- Phone-only alarms: the Police Security Systems site says audible-only alarms get no automatic police response. A self-monitored system has no police reference either, so if a photo shows a break-in, you dial 999 yourself.
- Standards and URN: the NPCC's 2026 requirements say the police issue a Unique Reference Number (URN) to your security company only for systems installed to listed standards, such as PD 6662 and BS 8243. You also need at least two trained keyholders who can attend within 20 minutes.
- False alarms: the same requirements withdraw police response after three false calls from an intruder alarm in a rolling 12 months. Ask the installer what your force applies.
We supply Ajax equipment; we are not installers and we do not sell monitoring. If you want police response, we can recommend a qualified installer depending on the job and area.
How do Ajax hubs report to you and to an ARC?
Every Hub 2 model sends push notifications, SMS and calls, and can report to an ARC over SIA DC-09, SurGard (Contact ID) or ADEMCO 685, according to Ajax's specifications. Connections run in parallel and switch over if one fails. Ajax lists all three as Grade 2 and PD 6662:2017 compliant, and says the hub warns users and the security company about radio jamming or lost devices.
| Hub | Connections | Ajax devices | Our price (inc VAT) |
|---|---|---|---|
| Ajax Hub 2 (2G) panel | Ethernet, two 2G SIMs | Up to 100 | £161.53 |
| Ajax Hub 2 (4G) panel | Ethernet, two 2G/3G/4G SIMs | Up to 100 | £228.45 |
| Ajax Hub 2 Plus panel | Ethernet, Wi-Fi, two 2G/3G/4G SIMs | Up to 200 | £268.10 |
Prices include VAT, delivery is extra and prices can change. See the full Ajax wireless alarm range.
What can a monitoring operator see?
A bare alarm signal says something triggered, not what. Ajax photo detectors fill that gap:
- The MotionCam photo-verification PIR (£124.61) takes pictures when it triggers while armed.
- The MotionCam U (PhOD) detector (£136.15) adds photo on demand, switched off by default.
- Ajax quotes delivery in up to 9 seconds at the default 320 x 240 resolution, or up to 20 seconds at 640 x 480.
Before you sign, note that Ajax's support notes say photos reach monitoring stations that use Ajax's own integration (Ajax Translator or PRO Desktop), while a plain SIA DC-09 link carries alarms but not photos. In 2021 Ajax announced integrations with two UK ARCs, EMCS and SMC.
Ajax also says operators can check footage from Ajax cameras and NVRs on the same system; Hub 2 (4G) accepts up to 25 IP cameras or DVRs. Place cameras with care: the ICO says data protection law applies when home cameras, including smart doorbells, record beyond your boundary.
Fire and carbon monoxide: who hears the alarm when nobody is in?
On an Ajax hub, a FireProtect 2 alarm reaches app users and, if monitored, the ARC. The detectors can interlink so all sound together.
- FireProtect 2 AC (Heat/Smoke/CO) (£105.00): mains powered with backup; Ajax lists it as Grade D1 under BS 5839-6.
- Sealed-battery FireProtect 2 SB alarms need no wiring; see the ones we list in our Ajax wireless fire alarms range.
- The AC model meets BS EN 14604 (smoke) and BS EN 50291-1 (carbon monoxide), per Ajax.
Under the Smoke and Carbon Monoxide Alarm (England) Regulations, landlords must fit a smoke alarm on every storey with living accommodation and, since October 2022, a CO alarm in any room with a fixed combustion appliance (gas cookers excluded). GOV.UK guidance recommends BS 5839-6 smoke alarms and sealed-for-life batteries where battery alarms are used. Every home in Scotland must have interlinked fire alarms.
Monitoring does not guarantee a fire engine at a business. London Fire Brigade does not attend automatic fire alarms between 7am and 8.30pm unless someone confirms a fire, although private homes and flats are exempt.
Does the landline switch-off change the decision?
GOV.UK guidance says analogue landlines are being switched off by January 2027, and alarm systems that rely on the phone line need upgrading. Ajax hubs do not use a phone line: they signal over Ethernet, SIM and, on Hub 2 Plus, Wi-Fi.
Which option suits your property?
Self-monitoring tends to suit:
- homes and flats where someone can always act on an alert
- lower-risk property where the insurer sets no monitoring condition
- people who want no contract
Professional monitoring tends to suit:
- shops, offices and units left empty overnight
- homes where the insurer asks for a monitored alarm
- owners who travel, or who look after a relative's home
- anyone who needs police response
The NPCC also advises written quotes from at least two approved companies, checking the company is acceptable to your insurer, avoiding long-term monitoring contracts and paying no more than a year in advance.
Our take
Decide on the response you need before the hardware. If a phone alert and your own 999 call are enough, an Ajax hub with MotionCam detectors gives you photo checks without a contract. If you need round-the-clock monitoring or police response, the same kit works; plan it with an approved installer from day one. A ready-made option is the Kit 25 S photo-verification kit with Hub 2 Plus (£664.87, delivery extra). Comparing brands? Our Hikvision AX PRO buying guide and Dahua AirShield alarm guide cover how those panels handle monitoring.
Questions about an Ajax system? Call 01902 902251, send us a message or visit our trade counter in Wolverhampton. Zenith Security Co. has been trading since 2012, and we ship nationally to England, Scotland and Wales.
Quick questions
Will my insurer accept a self-monitored alarm?
It depends on your policy. The NPCC advises checking that the system and company are acceptable to your insurer, so ask before you buy.
Can I add professional monitoring to an Ajax system later?
Yes. Ajax hubs report to ARCs over SIA DC-09, Contact ID or ADEMCO 685. For police response, an approved company must take the system on and arrange the URN.
Does Zenith provide the monitoring?
No. We supply the equipment; monitoring is a separate contract with an installer or ARC.
Will operators see my MotionCam photos?
Only if the ARC receives Ajax events through Ajax's own integration. Ask before you sign.
Source: Ajax Systems, Self-monitored vs. monitored security system; Ajax specifications for Hub 2 (4G), Hub 2 Plus, MotionCam U (PhOD) and FireProtect 2 AC; Ajax support, monitoring station connection; NPCC requirements (June 2026), Appendix H (February 2026) and Police Security Systems; Police Scotland FOI 23-2551; GOV.UK smoke and CO alarm guidance and landline switchover guidance; Scottish Government; London Fire Brigade; ICO; Ajax on EMCS and SMC.
