Unfortunately, data breaches are on the rise and a common trend in the modern business world. If your business processes personal data, keeping it safe and secure is critical.
But – mistakes can happen. An email containing personal details might go out to the wrong recipient in a rush, your business may be exposed to a cyber attack, or an employee might forget their laptop with sensitive client files on a train. These can all lead to data breaches. If a personal data breach occurs (and you're the data controller), you’ll need to act fast, as strict legal obligations will kick in, which you can’t ignore.
Ignoring a breach or handling it incorrectly can lead to serious consequences, including heavy fines. That's why it is key to identify a personal data breach and what steps to take if you experience one.
Our data protection solicitors explore key questions for data controllers about data breaches, how to react to them, and how to prevent them.
Jump to:
- What is a personal data breach?
- What should you do if there’s a personal data breach?
- Do you need to report a breach to the ICO?
- What needs to be included in an ICO notification?
- Do you need to notify individuals?
- How can your business prevent data breaches?
- Final thoughts: Be prepared, not just reactive
What is a personal data breach?
The ICO defines a personal data breach as a security incident that results in the accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to personal data.
It’s not just about data being stolen or leaked – even temporary unavailability of personal data can qualify as a breach, especially if it significantly negatively impacts individuals’ rights and freedoms.
Breaches can occur in many ways – from sophisticated cyber attacks to simple human error, like sending an email to the wrong person. That’s why your business needs to take a two-pronged approach: proactively minimise the risk of breaches and have a clear, effective response plan in place in case one does occur.
What should you do if there’s a personal data breach?
Every personal data breach must be assessed in line with data protection law – even if it initially seems low risk. Below are key steps to help guide your response:
- Record the breach immediately, regardless of its size. Document what happened, the potential impact, and the actions taken. You are legally required to keep records of all breaches, including those you decide not to report. The ICO may request to review these records at any time.
- Act quickly to investigate the incident, including the source, and take immediate steps to contain or mitigate the breach.
- Assess the potential risks to individuals and determine whether the breach needs to be reported to the ICO and/or the affected individuals. Time is of the essence – some breaches must be reported to the ICO within 72 hours.
- Understand the nature and severity of the breach. The level of harm depends on the type of data involved and how it might be misused. While some incidents may cause minor inconvenience, others – such as the exposure of health records, financial details, or identity documents – can lead to serious consequences like fraud or identity theft.
Do you need to report a breach to the ICO?
You must report a personal data breach to the ICO if it is likely to risk individuals’ rights and freedoms. The 72-hour reporting window (where feasible) starts when you become aware of the breach – even if you are still investigating the details.
Breaches can be reported via the ICO’s website.
When deciding whether a breach needs to be reported, consider the following:
- The type of breach (e.g. data theft, accidental loss, unauthorised access)
- The sensitivity of the data involved (e.g. special category data, financial information, health records, identity documents)
- Whether individuals can be identified from the data
- The potential harm the breach could cause (e.g. financial loss, identity fraud, emotional distress)
- The number of individuals affected
- Whether any vulnerable individuals (e.g. children) are impacted
If you determine that the breach is unlikely to result in harm, you do not need to report it – but you must document your decision and the reasons behind it.
Failure to notify a reportable breach may lead to penalties of up to £8.7 million or 2% of your global annual turnover. It is essential to take this obligation seriously, and you may wish to seek legal advice if you are unsure whether a breach is reportable.
What needs to be included in an ICO notification?
When reporting a breach to the ICO, you’ll need to provide a range of information, including:
- A description of the breach, with a summary of what happened – for example, what personal data was involved and, where possible, how many individuals were affected
- Contact details for your Data Protection Officer (DPO) or another appropriate contact person
- The likely consequences of the breach for individuals
- Details of the measures your organisation has taken, or plans to take, to contain the breach and mitigate its effects
- If you do not have all the necessary information within the 72-hour deadline, you must submit an initial report and provide further details as soon as possible.
Do you need to notify individuals?
You must notify individuals if the breach will likely result in a ‘high risk to their rights and freedoms.’ The assessment should be based on the specific circumstances of the breach.
If you determine that notification is required, you must inform individuals immediately.
When notifying individuals, you should clearly explain:
- A description of the breach, including what personal data was affected
- The potential consequences, such as the risks they may face and how they can protect themselves
- The steps your organisation has taken to address the breach
- Contact details for your Data Protection Officer (DPO) or another relevant contact person
- Practical advice, where appropriate, on what individuals can do to minimise potential harm
Clear, timely communication can help build trust and reduce the risk of further damage.
How can your business prevent data breaches?
Preventing a data breach before it happens is always the ideal approach. However, breaches are increasingly common and can still occur despite your best efforts. That’s why it’s crucial to take proactive steps now – not only to reduce the risk but also to demonstrate that you took reasonable precautions, which may help mitigate regulatory consequences in the event of an ICO investigation.
There are a number of practical measures your business can take. For instance:
- Encrypt sensitive data so it becomes unreadable if accessed by unauthorised individuals
- Use multi-factor authentication to protect user accounts
- Keep software and systems up to date with the latest security patches
- Limit access to personal data so that only authorised staff can view or process it
- Regularly test your systems for security vulnerabilities
Conducting routine risk assessments can help identify weaknesses early, and using pseudonymisation or anonymisation where appropriate can significantly reduce the impact of any breach.
If you work with third-party data processors, ensure any third-party data processing agreements clearly set out breach notification obligations and have a data breach response team in place to act quickly if a breach occurs. A well-designed data breach response plan ensures everyone knows their role and how to respond effectively.
Since many data breaches stem from human error, comprehensive staff training is essential to help your team recognise potential risks, follow security protocols, and respond appropriately.
For a broader look at cyber risks and how to protect your business, you may find our article on cyber security risks and the legal consequences of a cyber attack helpful.
Having access to a trusted data protection solicitor is also a wise move. If a breach does occur, they can help you determine whether it needs to be reported, assist with regulatory notifications, and respond to data subject queries. But legal support isn't just about damage control – early advice can help improve your internal policies, support effective training, and reduce the chances of future breaches.
Final thoughts: Be prepared, not just reactive
Personal data breaches carry high risks and demand a quick, structured response to meet strict regulatory deadlines. Every breach must be assessed, the risk evaluated, and decisions made about whether to notify the ICO and affected individuals. Mishandling or ignoring a breach can lead to serious penalties, enforcement action, and lasting reputational damage.
As you've seen, prevention is just as important as response. Proactive security measures, regular training, and a robust breach response plan can significantly reduce your exposure.
Whether strengthening your defences or dealing with an active breach, having the right legal guidance can make all the difference. Our data protection solicitors are here to support you – from preventing breaches to managing them effectively when they happen. The ICO also provides guidance on personal data breaches.
