Data breaches are a very real threat to UK organisations, with 43% of them reporting having suffered some kind of data breach in 2024. ISO/IEC 27001, or ISO 27001, sets out the requirements for establishing and maintaining an Information Security Management System (ISMS), helping organisations structure their approach to managing information risks and supporting effective responses to incidents.
This article explains how the ISO 27001 standard supports the effective management of data breaches, particularly in complying with UK GDPR’s 72-hour breach reporting window.
Read our guide to data breaches and why they’re so common.
0–24 Hours: Identification and Containment
The ISO 27001 standard includes requirements that support businesses in establishing clear processes for spotting and responding to information security issues within the critical first 24 hours.
Clause 6.1.3 of the standard requires the implementation of risk treatment plans to address identified threats. Annex A.5.23 emphasises clear responsibilities and documented procedures for managing information security incidents, while Clause 7.4 and Annex A.6.1 cover the planning of internal and external communications relevant to information security events.
Additionally, Annex A.5.10 specifies the need to record security events and preserve evidence.
In the event of a data breach, the immediate priority is to maintain composure and activate documented incident response procedures.
IT and security teams will immediately evaluate what data may have been compromised and identify the vulnerability exploited by the attackers. Organisations will then review and adjust access controls and credentials to secure systems following an incident. Once the initial scope of the breach has been assessed and affected stakeholders identified, transparent communication with customers and the press can help manage the situation effectively.
As many breaches have a financial nature, it is also best to contact all the banks and credit card issuing authorities connected with the compromised data. This way, they can stop or cancel transactions that appear fraudulent.
24–48 Hours: Impact Assessment
Between 24 and 48 hours after an incident, many organisations assess the potential impact, depending on the severity of the breach and established procedures.
Clause 9.1 and Annex A.5.26 require monitoring and evaluating security performance, including incidents.
Annex A.8.10 requires up-to-date records of processing activities, which helps in identifying whose data has been affected.
Annex A.5.31 requires organisations to identify, document, and manage all legal, regulatory, and contractual obligations relevant to information security, guiding the organisation’s compliance and response strategy.
48–72 Hours: Regulatory Notification
In the final 48 to 72 hours, organisations will focus on notifying the relevant bodies, the main one being the Information Commissioner’s Office (ICO).
This is mandatory under UK GDPR and the Data Protection Act 2018.
Clause 6.1.1 and Annex A.5.16 cover planning to fulfil regulatory and contractual responsibilities. UK GDPR mandates that personal data breaches meeting certain thresholds must be reported to the ICO within 72 hours.
If there is a high risk to individuals’ rights and freedoms, those affected must also be notified.
Annex A.8.11 discusses using encryption and pseudonymisation to reduce the severity of breaches.
Failing to report the data breach to the ICO, when required, could leave an organisation facing significant consequences, including potential fines up to £17.5 million or 4% of the organisation’s global turnover (whichever is higher) for serious infringements, legal action from those affected and reputational damage.
Other Supporting Activities
ISO 27001 also outlines supporting activities crucial during data breaches.
Annex A.6.3 and A.5.24 detail managing suppliers and external parties, including during breach incidents.
Clause 7.2 covers competence requirements for employees affecting information security, ensuring they are prepared for breach scenarios and are clear on their responsibilities.
Annex A.5.12 includes risk transfer options such as cyber insurance, offering a financial safety net.
Breach Examples and Control Mapping With ISO 27001
Real-world scenarios highlight the practical application of ISO/IEC 27001:2022 controls in managing and responding to data breaches.
For example, phishing attacks, where employees unintentionally disclose sensitive information to impersonators, are addressed through Annex A 6.3 – Information security awareness, education, and training. This control is designed to support personnel in recognising and responding appropriately to social engineering threats.
When insecure password practices lead to unauthorised access, Annex A 5.17 – Authentication information requires the implementation of strong authentication mechanisms to safeguard user credentials.
In instances where insufficient activity logging impairs incident detection, Annex A 8.15 – Logging and Annex A 8.16 – Monitoring activities ensure that access and system activities are recorded and monitored, enabling the early identification of anomalous behaviour.
To mitigate risks from third-party service providers, Annex A 5.19 – Information security in supplier relationships mandates the application of appropriate security measures and oversight across the supply chain.
By linking these controls to specific threat scenarios, organisations can see how ISO/IEC 27001:2022 supports the development of a context-driven, risk-based Information Security Management System (ISMS). This alignment enables organisations to design targeted and effective response and mitigation strategies that address real-world threats.
ISO 27001 Certification Overview
ISO 27001 sets out requirements for incident response, monitoring, logging, and continual improvement. Its requirements are designed to support the development of protective measures across all areas of information security, from handling physical documents to managing IT infrastructure and access control.
The standard’s adaptive guidelines allow organisations to respond quickly to emerging threats. When security patches are released to address software vulnerabilities, ISO 27001 supports the establishment of processes to address evolving threats, including updates to address software vulnerabilities.
ISO 27001 certification not only supports alignment with the Government Functional Standard for Security (GovS 007: Security), but also demonstrates an organisation’s commitment to maintaining and exceeding standard data security practices.
Meanwhile, the government-backed Cyber Essentials certification focuses on core technical controls, while Cyber Essentials Plus offers independent verification, both contributing to overall breach preparedness.
Protect Your Business From a Breach
Many organisations take measures such as introducing data security policies, regular penetration testing and multi-factor authentication to manage breach risks.
Achieving ISO 27001 certification is one of the most structured ways to strengthen defences against data breaches, allowing businesses to build robust protective policies across all areas. Thanks to the standard’s consistently evolving requirements, it allows businesses to take on new ideas and implement them at speed, helping them adapt swiftly to new threats.
Consider taking our Cyber Security training course to strengthen your awareness of cyber security best practices. During this 45-minute training course, expect to be introduced to topics such as:
- Password management
- Staying safe at work and at home
- Tips and techniques on safeguarding information
It’s designed to be an efficient and effective course that helps users understand the basics of cyber security.
By implementing ISO 27001 and related certifications, your organisation can build a robust defence against data breaches and effectively handle them if they do occur.
Contact our expert team to find out more, or to get a quote for your business.
