ISO 27001 Annex A 7.4 Physical Security Monitoring is an ISO 27001 control that requires an organisation to have a physical security perimeter to protect offices and processing facilities.
In this guide you will learn how to implement ISO 27001 Annex A 7.4 and pass your audit from ISO 27001 Lead Auditor Stuart Barker – author of the ultimate ISO 27001 Toolkit.
Table of contents
Purpose & Definition
ISO 27001 Annex A 7.4 is a preventive control and a detective control that ensures you detect and deter unauthorised physical access.
ISO 27001 defines ISO 27001 Annex A 7.4 as:
Premises should be continuously monitored for unauthorised physical access.
ISO27001:2022 Annex A 7.4 Physical Security Monitoring
ISO 27001 Annex A 7.4 Training Video
In this free training video you will learn How to implement ISO 27001 Physical Security Monitoring (Annex A 7.4) and Pass Your Audit.
Implementation Guide
General Guidance
You are going to have to
- define your physical security requirements based on business need and risk
- implement a topic specific Physical and Environmental Security Policy
- have a physical security perimeter for any physical location that processes information
- have alarms and monitors
- have an intruder response process
- meet all laws and regulations including those for fire and health and safety
ISO 27001 Physical Security Policy
To communicate to people what you do and what is expected you are going to write, sign off, implement and communicate your topic specific Physical and Environmental Security Policy.
Health and Safety
Your number one priority is to meet the requirements of law and regulation. Be sure to engage with a legal professional to understand what you can and cannot do and to check that you are not breaking any laws. The most significant laws are those around health and safety as the protection of human life and wellbeing is always our number priority. There are common things that should be considered such as fire suppression, fire doors, fire alarms, doors that fail open. Whilst we want to protect buildings and information our absolute priority is to protect people.
Alarms and Monitors
When looking at alarms and monitors you are looking at a preventive control to alert you when something has occurred. We all know what alarms are and getting alarms fitted is a very good idea. You want to define your response process and make sure that contacts of who is informed is up to date. Who is getting that call at 2am in the morning and what are they going to do when they get it?
CCTV
You can consider the use of CCTV but be aware that comes with some additional overheads with laws on data protection and the likes of GDPR. You should seek some legal advice before installing CCTV and be sure to do it in a way that is compliant if it is something that you do want to do. There are considerations such as how, how long, where, in what format you store the recordings. Then how do you get access to it, who can get access to it and how do you destroy it. It is not as simple as just banging up a Ring camera.
How to implement ISO 27001 Annex A 7.4
Implementing ISO 27001 Annex A 7.4 requires a proactive surveillance strategy to detect and respond to physical security breaches.
1. Define Secure Area Monitoring Requirements
Perform a site-specific risk assessment to identify the zones requiring continuous surveillance and the technical specifications needed for detection.
- Identify high-value assets and information processing facilities that necessitate 24/7 monitoring.
- Specify the required field of view and resolution for cameras to ensure forensic clarity for every entry point.
- Determine the sensitivity levels for motion, vibration, and infrared sensors to minimise false positive alerts.
- Document these requirements in a formal Physical Security Monitoring Policy.
2. Provision Technical Surveillance Systems
Deploy a combination of detective and deterrent hardware to ensure that any unauthorised physical access is immediately captured and logged.
- Install a Video Surveillance System (VSS/CCTV) with motion-triggered recording and encrypted storage.
- Provision an Intrusion Detection System (IDS) that is linked to a central alarm receiving centre.
- Ensure all surveillance hardware is protected from physical tampering and environmental interference.
- Configure automated health checks to alert the IT Operations team if a camera or sensor goes offline.
3. Formalise Monitoring Logs and Retention Protocols
Establish a rigorous data management process for surveillance footage and access logs to maintain an audit trail that complies with legal and regulatory standards.
- Set a mandatory retention period for CCTV footage, typically between 30 and 90 days, in accordance with local data protection laws such as GDPR.
- Implement Write-Once-Read-Many (WORM) storage for logs to prevent unauthorised deletion or modification.
- Encrypt all monitoring data at rest to prevent the exfiltration of sensitive site information.
- Revoke logical access to monitoring dashboards for any personnel who no longer require it for their role.
4. Execute Regular Monitoring Log Reviews
Conduct periodic audits of surveillance data to identify anomalous patterns and verify that the monitoring systems are functioning as intended.
- Perform a weekly review of physical access logs against CCTV footage on a sample basis.
- Document the findings of every review in a formal report signed by the CISO or Facilities Manager.
- Investigate any discrepancies between badge-in events and visual confirmations immediately.
- Maintain these review records as primary evidence for external ISO 27001 certification audits.
5. Integrate Monitoring with Incident Response Protocols
Link physical monitoring alerts to your organisation’s broader incident management framework to ensure a rapid and co-ordinated response to breaches.
- Define automated escalation paths for different alarm types, such as forced entry versus door-held-open alerts.
- Provision Multi-Factor Authentication (MFA) for remote access to security dashboards by response teams.
- Establish a Register of Entrants (ROE) for any emergency maintenance personnel attending a physical breach.
- Perform quarterly drills to test the speed and effectiveness of the response to a physical monitoring alert.
How to pass the audit
To implement ISO 27001 Annex A 7.4 you are going to:
- Define your external physical perimeter requirements
- Define your monitoring requirements
- Define your internal sub zone physical perimeter requirements
- Consult with a legal professional to ensure you are meeting legal and regulatory requirements
- Implement your physical security perimeters
- Implement your monitors
- Write, sign off, implement and communicate your topic specific Physical and Environmental Security Policy
- Write, sign off, implement and communicate your perimeter incident response procedures
- Implement a process of internal audit that checks that the appropriate controls are in place and effective and where they are not follow the continual improvement process to address the risks
What the auditor will check
The audit is going to check a number of areas. Lets go through them
1. That you have a physical security perimeter
One of the easier things for an auditor to check is the physical security perimeter as it is usually the first thing they will encounter when they come to audit you if you have a physical location. For all the physical locations in scope they are going to visit and check.
2. The physical security monitors that you have in place
They have been doing this a long time and done many audits so they know what to look for. They will test the controls and see what happens. They will try to open doors, open cupboards, gain access to areas they should not. Your monitors should be such that they can respond to this. They will also look to see that you have tested the monitors in the last 12 months.
3. Documentation
They are going to look at audit trails and all your documentation. They will look at appropriate access reviews, logs of monitors and reports, incidents and how you managed them.
Top 3 mistakes and how to avoid them
The top 3 mistakes people make for ISO 27001 Annex A 7.4 are
1. Your physical security monitoring is turned off
What do I mean by turned off? In simple terms it means that you have a camera that works on a battery and the battery is dead. Or you have just turned the camera off. Perhaps someone has disconnected an alarm because it goes off all the time and annoys them.
2. One or more members of your team haven’t done what they should have done
Prior to the audit check that all members of the team have done what they should have. Have you tested the security monitoring? Who gets informed about the alarm and do they still work here?
3. Your document and version control is wrong
Keeping your document version control up to date, making sure that version numbers match where used, having a review evidenced in the last 12 months, having documents that have no comments in are all good practices.
ISO 27001 Annex A 7.4 FAQ
No, CCTV is not strictly mandatory under ISO 27001, but it is the industry-standard technical control for satisfying the requirement for continuous physical monitoring.
Organisations must use a risk assessment to justify the choice of monitoring tools.
Alternative controls include physical security guards, vibration sensors, or infrared beams.
If implemented, CCTV systems must be protected from tampering and unauthorised viewing.
Privacy regulations like GDPR must be documented within the monitoring policy.
Retention periods for physical security logs and CCTV footage should be defined by your organisation’s risk assessment while remaining compliant with local data protection laws.
A common industry standard for retention is between 30 and 90 days.
Logs must be stored securely to prevent unauthorised deletion or modification.
Footage used as evidence in an incident must be preserved until the investigation closes.
Retention policies must include a formal process for the secure disposal of old data.
Organisations typically deploy a combination of detective and deterrent systems to maintain the integrity of their physical perimeters.
Video surveillance systems (CCTV) with motion-triggered recording.
Intrusion Detection Systems (IDS) linked to an alarm receiving centre.
Physical Access Control Systems (PACS) that log every badge-in/badge-out event.
Environmental sensors for detecting fire, heat, or water leaks in server rooms.
Responsibility usually resides with the Facilities Management or IT Operations team, with overall oversight provided by the Chief Information Security Officer (CISO).
Internal staff or third-party security contractors may perform live monitoring.
Roles and responsibilities must be clearly defined in the Physical Security Policy.
Monitoring personnel must receive specific training on incident escalation procedures.
Regular audits verify that the assigned personnel are performing required log reviews.
Yes, if a risk assessment determines that sensitive assets are processed in remote locations, appropriate physical monitoring or procedural controls must be implemented.
Focuses on the “secure zone” within the home where work is performed.
Controls usually favour procedural habits over invasive technical monitoring.
May include use of lockable cabinets or basic home alarm systems.
Remote monitoring is often supplemented by logical access logs on company devices.
Related ISO 27001 Controls
- ISO 27001 Annex A 7.1 Physical Security Perimeters
- ISO 27001 Annex A 7.5 Protecting Against Physical and Environmental Threats
ISO 27001 Annex A 7.4 Attribute Table
| Control type | Information security properties | Cybersecurity concepts | Operational capabilities | Security domains |
|---|---|---|---|---|
| Preventive | Confidentiality | Protect | Physical_security | Protection |
| Detective | Integrity | Detect | Defence | |
| Availability |
Stuart Barker
Stuart Barker is qualified ISO 27001 Lead Auditor and a veteran practitioner with over 30 years of experience in systems security and risk management. Holding an MSc in Software and Systems Security, he combines academic rigour with extensive operational experience, including a decade leading Data Governance for General Electric (GE).
Now he is founder and Lead ISO 27001 Consultant at High Table, the worlds number 1 dedicated ISO 27001 Consultancy.
