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The Most Common Data Protection Incidents (And How to Prevent Them)

Written by Annabelle Ilsley | Mar 31, 2026 4:29:25 PM

When people think about data protection incidents, they tend to picture something dramatic - a cyber attack, a system being hacked, or a ransomware demand making headlines.

But that isn’t what most data protection incidents actually look like.

According to the ICO’s Data Security Trends report, the majority of reported incidents are far more ordinary. They happen in the flow of day-to-day work, and usually without any malicious intent.

They’re consistent, repeatable patterns, and that’s exactly why they matter. Because if incidents are predictable, they’re also preventable.

In this blog, we’ll be looking at:

 

What Are The Most Common Data Protection Incident Types?

Looking at the ICO’s Data Security Trends report for 2025, the most common incident types include:

  • Data emailed to the wrong recipient (18%)
  • Unauthorised access (12%)
  • Phishing (11%)
  • Failure to redact (7%)
  • Data sent by post or fax to the wrong recipient (5%)

What really stands out here isn’t just the volume, it’s the nature of these incidents.

None of them rely on advanced technical exploits or sophisticated attacks. Instead, they all have one clear thing in common: they come down to user behaviour.

And more importantly, they’re all avoidable with clear, consistent training.

 

What Incidents do the ICO Actually Investigate?

Not every reported incident leads to enforcement. But the ones the ICO does investigate tell you something important - what actually matters from a regulatory perspective.

They’re not just looking at what happens most often, they’re looking at what creates real risk.

When you look at the cases pursued, a few categories come up repeatedly:

  • Unauthorised access
  • Ransomware
  • Phishing
  • Malware
  • Failure to redact

At first glance, this might look slightly different from the most common incidents. But when you step back, the same themes are still there.

Unauthorised access and failure to redact sit firmly in both lists. Even phishing and malware, while more technical on the surface, still rely heavily on human behaviour — someone clicking, downloading, or trusting something they shouldn’t.

And it all comes back to how data is handled day to day. Who has access to it, and whether people recognise risk in the moment.

 

Why These Incidents Keep Happening

It would be easy to put these incidents down to carelessness, but that’s not really what’s going on.

Most teams are moving quickly, juggling priorities, and handling more data than ever. In that environment, mistakes aren’t surprising, they’re inevitable without something in place to guide better decisions.

And without that awareness, the same incidents happen again and again, regardless of how many policies or tools are in place.

 

How to Prevent the Most Common Data Protection Incidents

When you look at the types of incidents being reported and investigated, prevention doesn’t need to be complicated. It comes down to getting the basics right, consistently.

For each of the most common issues, there are clear, practical ways to reduce risk:

  • Data emailed to the wrong recipient
    Build simple verification habits. Double-check recipients, especially when sending sensitive data, and slow things down at the point of sending, not after.
    This is where training makes a real difference. Scenario-based examples, like sending the wrong attachment or selecting the wrong contact, help people recognise these risks in context.

  • Unauthorised access
    Keep access tightly controlled and regularly reviewed. People should only have access to what they need and nothing more.
    This comes down to having clear access control policies in place. Who has access to what, when access should be granted, and just as importantly, when it should be removed. That includes making sure access is revoked immediately when someone changes roles or leaves the business.

  • Phishing and malware
    Help teams recognise what suspicious activity actually looks like in practice, not just in theory. Most incidents happen because something “looked normal” in the moment.
    Regular training is key here, especially when it includes real-world examples and simulated phishing attacks. The more familiar these threats feel, the easier they are to spot and avoid.

  • Failure to redact
    Make it clear what needs to be removed before sharing information, and how to do it properly. Don’t assume people know, show them.
    In most cases, mistakes happen because people aren’t confident in what should be redacted or how to do it correctly. Clear, practical guidance goes a long way.

  • Data sent to the wrong recipient (post or email)
    Reinforce the importance of pausing before sharing. Most of these incidents happen in seconds, but that’s exactly where a small check makes the difference.
    Again, this comes back to training. Regular reminders and real-world scenarios help build that instinct to stop and sense-check before anything is sent.

 

How Training Prevents Common Data Protection Incidents

People are always going to make mistakes, that’s inevitable. But a large proportion of these incidents can be avoided when people know what to look for and what to do in the moment.

That’s where training makes the difference.

For it to actually work, training needs to be:

  • Regular - so it isn’t forgotten
  • Engaging - so people pay attention
  • Relevant - so it reflects the situations they deal with day to day

Without that, it becomes a tick-box exercise - completed, but not applied.

And if your organisation processes personal data, this goes beyond best practice. Under the GDPR, you’re expected to put appropriate measures in place to protect that data, including ensuring staff are properly trained and aware of their responsibilities.

 

Data Protection Training That Actually Works

At Trust Keith, our training is designed around how incidents actually happen, so teams don’t just complete it, they apply it.

  • Tailored to your team and your risks
    Trust Keith identifies where your biggest risks sit, then adapts training to each role and department so it’s relevant from day one.

  • Built for real-world scenarios
    From misdirected emails to phishing attempts, training focuses on the situations your team actually faces.

  • Engaging by design
    Interactive scenarios, short videos, quizzes, and live expert sessions keep people engaged, so the learning sticks.

  • Clear visibility of human risk
    Track progress, monitor results, and see where gaps remain, so you can improve over time and demonstrate impact.