Lockdown alarm, PA or app? How to choose a lockdown alert for your school
Updated 30 September 2026
There's no single right answer, and many schools end up with more than one layer. What matters is whether your signal reaches every adult quickly, can't be mistaken for the fire alarm, and doesn't tell an intruder what you're doing.
This guide sets out what any lockdown alert has to do, the strengths and limits of each option, and the questions to ask before you buy.
What any lockdown alert has to do
- Reach everyone, fast. The Martyn's Law guidance asks you to think about where people will be and whether the message will reach them there: classrooms, offices, the field, the dinner hall at break.
- Sound nothing like the fire alarm. The DfE says the lockdown alert "must differ in some way from the actual fire alarm sound". The Fire Industry Association's guidance for schools adds that fire evacuation tones shouldn't be used for anything else, and that lockdown beacons should be a different colour.
- Stay quiet when it needs to. The DfE's lockdown template advises silent communication wherever possible when an intruder may be close.
- Tell staff what to do. A signal says something is wrong. Instructions say lock the door, close the blinds, keep away from the windows.
- Show who is safe. Leaders need to know which rooms are secure and who needs help.
- Give a clear all clear. The DfE template asks for a separate stand-down signal, so nobody unlocks too early.
- Work for everyone. ProtectUK says alarms must be heard, seen or otherwise perceived by everyone, including people who are deaf or hard of hearing.
- Be easy to practise. Testing and drills are part of the procedure, so the system should make them simple and leave a record.
The three main options
A dedicated lockdown alarm
Call points, sounders with their own tone, beacons and key fobs, wired or wireless. Wireless systems use their own radio link, so a site survey checks the range.
Strengths- Everyone hears it, including visitors and people outdoors
- Nobody needs a device to hand
- Simple to understand
- An intruder hears it too
- It says something is wrong, not what to do
- It can't tell you who is safe
- Installation, testing and maintenance
PA or tannoy announcements
A spoken message, live or pre-recorded, through speakers across the site.
Strengths- Carries spoken instructions
- Can reach outdoor areas with the right speakers
- Pre-recorded messages remove guesswork
- Everyone hears it, pupils and intruder included
- Needs power, and someone at the microphone
- One way only: no replies
- Wording needs care under pressure
A staff alert app
Alerts to the phones, tablets and computers staff already use, often with a full-screen alert on desktops.
Strengths- Instructions reach every adult, silently if needed
- Staff reply, so leaders see who is safe
- Any member of staff can raise the alarm from anywhere
- Every step is recorded
- Staff need a device with them and alerts switched on
- Visitors and pupils need another route
- Check how it behaves if the network goes down
Layers that work together
A distinct audible signal for outdoor areas and visitors, and a staff app for instructions, replies and the record. Each covers the other's blind spots.
Worth checking- Can one action trigger both?
- Do both use the same words for the same thing?
- Who gives the all clear, and how?
We needed a system where staff could get the message whether they sat at the computer or via an app on their phone while working outdoors. teamSOS seamlessly filled the gap.
Questions to ask any supplier
- Can any member of staff raise the alarm, or only from fixed points?
- How is the lockdown signal different from our fire alarm?
- Can we send an alert without a sound?
- How do we know who is safe, and who needs help?
- Does it reach staff outdoors, and does it work if our Wi-Fi or network is down?
- Can visitors on site be alerted?
- How do we run a drill, and what record do we get afterwards?
- What will it cost over five years, including installation, maintenance and replacement parts?
Costs and funding
Alarm hardware is usually a one-off purchase plus installation, with testing, batteries and maintenance to follow. Apps are usually an annual subscription with no hardware. Compare them over five years, not in year one.
Don't count on the Condition Improvement Fund. Its 2026 to 2027 guidance focuses on building condition, rules out ICT software, and says security projects need strong evidence, such as police reports, to succeed.
teamSOS Lockdown starts from £350 a year for a primary school and £650 for secondary and SEN schools. It runs on the devices staff already use, works over mobile data on phones if the school network goes down, and can extend alerts to signed-in visitors if you use InVentry.
Sources: Martyn's Law statutory guidance (Home Office, updated 25 August 2026); Protective security and preparedness for education settings (DfE, April 2025); DfE lockdown template; FIA guidance note on fire alarm systems and lockdown in schools (May 2025); ProtectUK on evacuation, invacuation and lockdown; Condition Improvement Fund guidance.
See teamSOS in action
Book a 15-minute demo and bring your questions. We'll show you a lockdown from first alert to all clear.
