Organisations deploying biometric technologies must understand that these systems trigger some of the most stringent obligations in EU data protection law
Biometric technologies are increasingly used by organisations for authentication, identity verification, fraud prevention, workplace monitoring, and access control. While these systems are often marketed as efficient and secure, their deployment creates significant compliance risks under the General Data Protection Regulation (GDPR). Businesses must recognise that biometric data can constitute special category personal data and therefore requires enhanced safeguards, clear legal bases, and careful proportionality assessments before implementation.
Biometric data is not always special category data but becomes so when used for identification purposes
Under the GDPR, biometric data refers to personal data resulting from specific technical processing relating to physical, physiological, or behavioural characteristics that enable or confirm the unique identification of a natural person. This means that raw biometric measurements, such as a photograph or voice recording, do not automatically fall within the special category regime. However, once such data is processed through algorithms to create biometric templates used to uniquely identify an individual, stricter Article 9 GDPR requirements apply. Organisations must therefore carefully determine whether their systems involve biometric identification or merely biometric detection or categorisation.
Deploying biometric systems typically requires a valid Article 9 legal basis in addition to a lawful basis under Article 6 GDPR
Where biometric data is processed for the purpose of uniquely identifying individuals, organisations must identify both a lawful basis for processing and an additional condition for processing special category data. In many commercial contexts, explicit consent is considered the most appropriate legal basis. However, consent must be freely given, specific, informed, and capable of withdrawal. This may be difficult to achieve in certain environments, such as employment relationships or situations where access to essential services is contingent on biometric enrolment. Organisations must therefore evaluate alternative legal grounds and ensure that biometric processing is strictly necessary and proportionate.
Supervisory authorities increasingly scrutinise necessity and proportionality in biometric deployments
Data protection authorities across Europe have repeatedly emphasised that biometric technologies should not be deployed simply because they are convenient or innovative. Organisations must demonstrate that less intrusive alternatives, such as PIN codes or access cards, would not adequately achieve the intended purpose. Failure to conduct such assessments has led to enforcement action in several Member States, particularly in cases involving workplace attendance systems or facial recognition access controls. Regulators have also stressed that biometric processing may lead to heightened risks of surveillance, discrimination, or exclusion.
Recent enforcement activity highlights the financial and reputational risks of non-compliant biometric processing
Recent decisions illustrate that biometric deployments can result in significant penalties where organisations fail to comply with GDPR principles. For example, supervisory authorities have imposed fines on companies using fingerprint attendance systems without demonstrating necessity or obtaining valid consent. In addition, investigations into large-scale facial recognition databases and unlawful scraping of biometric images have reinforced regulatory expectations regarding transparency, lawful basis, and purpose limitation. These enforcement trends signal that biometric compliance is becoming a priority area for regulators.
Organisations implementing biometric technologies should conduct Data Protection Impact Assessments at an early stage
Because biometric processing often involves systematic monitoring, innovative technology, and the processing of special category data, it will frequently trigger the requirement to conduct a Data Protection Impact Assessment (DPIA). A DPIA enables organisations to assess risks to individuals’ rights and freedoms, evaluate proportionality, and identify mitigation measures before deployment. Conducting a DPIA early in the procurement or design phase can help avoid costly redesigns, regulatory investigations, or reputational damage.
DPOs and privacy consultants like Aphaia can help organisations conduct DPIA for systems based on biometric data.
Security, storage limitation, and function creep represent key operational risks in biometric systems
Unlike passwords or access cards, biometric identifiers cannot be changed if compromised. This creates long-term risks in the event of security breaches. Organisations must therefore implement sound technical and organisational measures, such as encryption, template storage rather than raw image retention, strict retention schedules, and access controls. They must also guard against function creep, whereby biometric data collected for one purpose is subsequently used for unrelated monitoring or profiling activities.
Biometric governance frameworks will become increasingly important as AI-driven systems expand
The growing integration of biometric analysis into artificial intelligence systems, including facial recognition, voice analysis, and behavioural prediction tools, is expected to intensify regulatory scrutiny. Emerging regulatory frameworks, such as the EU Artificial Intelligence Act, introduce additional compliance obligations and risk classifications for certain biometric uses. Organisations deploying biometric technologies must therefore adopt forward-looking governance strategies that consider both existing GDPR requirements and evolving AI regulatory expectations.
