An alarm receiving centre (ARC) is a 24/7 control room that answers lone worker alarms, assesses what is happening and escalates to help. In an audited BS 8484:2022 service, the ARC operates to BS 9518 and holds the police unique reference numbers (URNs) that unlock a fast-tracked response.
What an ARC does with an alarm
When a device or app raises a red alert, the ARC receives the wearer's identity, their location and a live audio channel. The operator's first job is to listen. Trained operators can often assess a situation without speaking, which matters when a worker cannot talk safely. The second job is decision: false activation, situation resolved, contact a manager, or emergency.
Escalation follows a protocol agreed with the employer in advance: which contacts are called, in what order, and what evidence justifies calling the police. The ARC logs every step, which is why audited services can reconstruct an incident minute by minute afterwards, and self-monitored arrangements usually cannot.
The standards behind a compliant ARC
Since the 2022 edition of BS 8484, the ARC requirements live in their own standard, BS 9518, which covers centres handling alarms that may need a police response. Centres are also commonly certified to BS EN 50518, the European standard for monitoring centre construction and operation, and screen their staff to BS 7858. When a supplier claims accreditation, those are the designations to look for alongside BS 8484:2022 itself; the main guide explains how the pieces fit together.
One structural detail is worth checking: whether the operators who answer lone worker alarms do only that work, or juggle it with CCTV, intruder and fire monitoring. Dedicated lone worker operators hear more real incidents and handle the listening-without-speaking cases better.
The URN scheme and Level 1 response
A unique reference number is issued to a qualifying ARC by a police force under national policing guidance [VERIFY: current NPCC guidance title and date]. It functions as pre-cleared credibility. When an operator confirms a genuine emergency, they contact the force control room directly, quote the URN, and request a Level 1 response, the highest priority the force offers. The call bypasses the public 999 queue entirely.
The scheme exists because police forces need to trust the source before committing an immediate response to a third-party alarm. The audit trail behind the URN, the standards above, is what earns that trust. It cannot be bought separately from the audit, which is why an unaudited service, whatever its hardware, routes emergencies through 999 like any member of the public.
Important: A URN belongs to the monitoring arrangement, and misuse puts it at risk. Repeated false calls to police through the URN route can lead to a force withdrawing the response. Good ARCs guard the threshold: escalation protocols exist to protect the response for the incidents that need it.
Self-monitoring compared
Some services offer a cheaper tier where alarms route to managers instead of an ARC. That can be a reasonable fit for pure check-in discipline in low-risk roles. It is not an emergency arrangement. Managers sleep, sit in meetings and miss notifications, and a manager receiving an alert at 2am has no URN, no training in silent listening and no logged procedure. If the risk assessment found any realistic emergency scenario, monitoring belongs with an ARC.
Questions to ask a monitoring provider
- Which standards is the ARC itself certified against, and can you see the certificates?
- Do the operators handle lone worker alarms exclusively?
- What is the escalation protocol on a missed check-in, step by step, with timings?
- How many centres are there, and what happens if one goes down?
- What does the incident log look like afterwards, and who gets access to it?
Suppliers whose monitoring has passed the audit are listed in the accredited companies directory.