How to Prevent Data Breaches Caused by Human Error

Protection Group International’s Governance, Risk and Compliance Team

Human error contributes to up to 95% of data breaches, according to a 2024 Mimecast study. Despite advanced cybersecurity tools, a misdirected email, weak password, or accidental data exposure can cause serious financial and reputational damage.

In late 2024, Lloyds Banking Group suffered a data breach when a customer received confidential investment statements intended for others. Names, addresses and portfolio details were exposed—highlighting how even simple errors can have serious consequences.

To reduce the risk of incidents like this, organisations must build robust data handling processes. While some level of human error is inevitable, well-structured procedures, training and controls can significantly reduce both likelihood and impact.

What is a personal data breach?A personal data breach involves the accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to personal data. Under UK GDPR, organisations must:

• Know how to recognise a breach

• Have clear detection, investigation and reporting procedures

• Ensure staff report incidents appropriately

Non-compliance risks fines from the Information Commissioner’s Office (ICO).

How human error causes breachesEven well-defended systems are vulnerable to everyday mistakes. Common causes include:

• Misdirected emails – Sensitive info sent to the wrong person

• Weak or reused passwords – Easily exploited by hackers

• Phishing attacks – Clicking malicious links or sharing credentials

• Public Wi-Fi use – Exposing devices to interception

• Misconfigured systems – Unsecured platforms due to poor setup

These errors may seem minor but can result in significant data leaks, penalties, and reputational loss.

Build a stronger internal framework

Human error should be addressed as part of your broader risk strategy. Clear policies, procedures, and a culture of awareness reduce the chance and consequences of breaches.

Start with a cybersecurity framework

Standard frameworks support security and compliance:

• Cyber Essentials – Government-backed baseline protections

• Gap Analysis – Identify weaknesses and areas for improvement

• ISO 27001 – Advanced security framework for mature organisations

Strengthen IT controls

Minimise human error with smart safeguards:

• Apply the principle of least privilege – Limit access to only what’s necessary

• Restrict external email use to reduce leaks

• Use tools like Microsoft 365 encryption, delay send, and attachment blocking

• Limit file sharing in Teams, OneDrive, and SharePoint

• Use web filtering and CASBs to block risky apps and platforms

Educate your staff

Your people are your first and last line of defence:

• Mandatory data protection and phishing training

• Annual (or 6-monthly) refreshers for high-risk teams

• Regular internal comms and reminders

• Clear reporting procedures

• A culture where questions and concerns are encouraged

While human error can’t be eliminated, the right mix of controls, culture and training can prevent costly breaches.

At PGI, our Information Assurance and GDPR & DPA consultancy helps organisations of all sizes reduce their exposure to human error. We combine technical know-how with regulatory insight to build secure, compliant processes. Get in touch to find out how we can help.