How GDPR Affects Biometric Access Control Systems in the Workplace

In modern workplaces, the integration of biometric access control systems has increasingly become the norm. These systems, which use physical or behavioural characteristics—such as fingerprints, facial recognition, voice patterns, or even iris scans—are lauded for their high levels of security and convenience. However, as biometrics have become more prevalent, so too have concerns regarding privacy, data protection, and employee rights. Nowhere is this more evident than in the European Economic Area, where the General Data Protection Regulation (GDPR) sets stringent requirements for the processing of personal data, particularly when it concerns sensitive data such as biometrics.

What Makes Biometric Data ‘Special’?

Biometric data holds a unique position under data protection law because of its inherently personal nature and potential to cause significant harm if misused. Under GDPR, biometric data is classified as a special category of personal data. Article 9 of the regulation explicitly prohibits the processing of special categories of data unless specific conditions are met. The reason for this high level of protection is straightforward: while a password or ID badge can be changed if compromised, biometric characteristics like fingerprints or facial features are immutable and unique to each individual. Misusing this data can potentially jeopardise one’s identity for life.

This classification has profound implications for employers who wish to implement biometric access controls. Unlike conventional authentication methods, using biometrics in the workplace cannot be justified merely on grounds of convenience or cost-efficiency. Employers must tread carefully, ensuring compliance with data protection laws to avoid significant legal and reputational consequences.

Lawful Basis for Processing Biometric Data

To legally process biometric data under GDPR, an organisation must establish a lawful basis under Article 6 and meet at least one condition from Article 9(2). The most applicable grounds in the employment context usually fall under explicit consent or necessity for carrying out obligations in the field of employment.

However, relying on consent in employment settings is fraught with challenges. Consent under GDPR must be freely given, specific, informed and unambiguous. Given the inherent power imbalance between employer and employee, supervisory authorities often argue that it is difficult to obtain valid, freely-given consent in the workplace. An employee might feel compelled to consent to biometric data processing out of fear that refusal could lead to negative repercussions, regardless of reassurances.

This leaves necessity as the other potential lawful ground. The employer must demonstrate that collecting biometric data is genuinely necessary for a purpose permitted by law—typically related to health, safety, or legitimate security concerns—and that no less intrusive means are available. If alternative methods, like swipe cards or PINs, provide a similar level of security, then biometric methods might not meet the necessity test.

Data Minimisation and Purpose Limitation

Two of GDPR’s core principles—data minimisation and purpose limitation—also come into sharp focus in the context of biometric systems. Data minimisation requires organisations to collect only the data that is strictly necessary for the stated purpose. Purpose limitation requires that the collected data be used solely for the specific reason for which it was obtained.

In practice, this means that employers should not retain biometric data for purposes beyond access control unless they have specifically informed employees and obtained appropriate lawful basis. For example, using the same biometric data to monitor employee attendance, while initially collected for security access, could breach the principle of purpose limitation unless properly disclosed and justified.

Furthermore, the technology designed to gather biometrics should be configured to capture the minimal amount of data necessary for effective functioning. For instance, some systems create and store a mathematical representation (template) of a fingerprint rather than storing the image itself, thereby reducing the risk of identity theft. The use of pseudonymisation and encryption becomes not only a good practice but, in many cases, a necessary requirement under GDPR.

Transparency and Employee Rights

Another cornerstone of GDPR is transparency. Employers must inform employees clearly and comprehensively about the biometric systems in use, including details such as:

– What data will be collected and for what purpose
– How long the data will be stored
– Who will have access to the data
– The measures in place to protect the data

This is usually articulated in a privacy notice or written policy. Such transparency empowers employees to understand their rights and how their data is being processed.

In addition to transparency, employees have several rights under GDPR that are particularly pertinent when biometrics are involved. These include:

– The right to access their own data
– The right to rectification of inaccurate data
– The right to erasure (‘right to be forgotten’)
– The right to restrict or object to processing
– The right to data portability, where applicable

Importantly, the right to erasure can be complex when dealing with biometric systems. If an employee leaves or withdraws consent, their biometric information must be promptly and securely deleted, and the organisation must be able to demonstrate how this is done. Retaining such data longer than necessary, even for back-up or audit purposes, can lead to serious non-compliance issues.

Security of Biometric Data

Given the high sensitivity of biometric data, GDPR places a strong emphasis on data security. Organisations are required under Article 32 to implement “appropriate technical and organisational measures” to ensure a level of security appropriate to the risk. This involves considering potential physical, technical, and human threats.

For biometric systems, security best practices might include encryption, two-factor authentication for system administrators, rigorous access control policies, regular vulnerability testing, and a clear data breach response plan. Since biometric breaches can have severe consequences—not just for individuals but for the organisations involved—taking a proactive approach to security isn’t merely advisable, it’s a legal obligation.

Unfortunately, many employers underestimate this responsibility. There have been documented cases where employers stored raw fingerprint images instead of encrypted templates, or used commercially-available biometric scanners without verifying their compliance measures. Such oversights can result in significant fines, not to mention reputational damage.

Data Retention and Storage Concerns

Proper data retention policies are another crucial aspect of compliance. GDPR mandates that personal data should be kept only for as long as necessary. In the context of biometric systems, this means data should be deleted, anonymised, or securely archived as soon as the employee exits the organisation or the data is no longer required for its original purpose.

This presents challenges for many organisations that operate with legacy or poorly integrated systems. Ensuring that biometric data is automatically deleted when employment ends, without manual oversight, requires a high degree of technical coordination. Failing to do so can result in dormant data sitting invisibly in the system, creating a ticking compliance time-bomb.

Moreover, organisations using third-party vendors for their biometric systems must ensure that these providers also adhere to GDPR standards. Contracts should clearly delineate the vendor’s responsibilities, particularly regarding data retention, deletion upon request, and data security protocols.

Cross-Border Transfers and Third-Party Providers

If an employer uses a biometric system provided by a vendor outside the EU/EEA, any transfer of biometric data across borders must comply with Chapter V of the GDPR. This typically means ensuring that the third country offers adequate data protection measures, or applying Standard Contractual Clauses approved by the European Commission.

This is a complex area with evolving legal interpretations, particularly since the ‘Schrems II’ case invalidated the EU-US Privacy Shield, leading to greater scrutiny of data transfers to the United States. Employers must conduct detailed Transfer Impact Assessments to ensure adequate safeguards are in place, and should avoid any vendor who cannot clearly demonstrate privacy compliance.

The Role of Data Protection Impact Assessments (DPIAs)

Under Article 35 of the GDPR, if data processing is likely to result in a high risk to individuals’ rights and freedoms, the employer must carry out a Data Protection Impact Assessment (DPIA) prior to implementation. The use of biometrics, particularly on a large scale or in public-access areas, almost always meets this threshold.

A DPIA involves identifying and evaluating potential risks to data subjects and then implementing measures to mitigate those risks. This should be a documented process involving consultation with internal stakeholders and possibly seeking advice from a Data Protection Officer or supervisory authority.

In the event of a data protection audit or investigation, having a properly executed DPIA can demonstrate that the organisation took its compliance responsibilities seriously. Conversely, failure to conduct a DPIA where required can itself be deemed a GDPR violation.

Cultural and Ethical Considerations

Beyond legal compliance, the use of biometric technology raises important ethical and cultural issues in the workplace. Employees may feel that their privacy is being infringed upon or that they are being subjected to surveillance, even if technically within legal bounds. Addressing these concerns requires more than just legal manoeuvring—it demands clear communication, inclusive decision-making, and sensitivity to employee perceptions.

Employers should involve staff early in the decision process, provide opt-out alternatives wherever feasible, and remain open to feedback. Building trust around data protection and respecting workers’ dignity isn’t just the right thing to do—it can also enhance morale and productivity.

Final Thoughts

As biometric technologies continue to permeate the modern workplace, their potential to fundamentally transform access control is clear. However, with great power comes great responsibility. In the eyes of GDPR, biometric data is among the most sensitive information an employer can collect. Navigating the complex web of consent, lawful basis, data minimisation and employee rights requires a strategic, respectful, and compliance-first mindset.

Organisations that fail to take these responsibilities seriously risk not only legal penalties but the erosion of employee trust and satisfaction. On the other hand, those who approach biometric implementation thoughtfully, ethically and in full alignment with legal frameworks will be well-placed to harness the benefits of this promising technology while maintaining the highest standards of data protection.