Trade Union Membership Data

Information revealing an individual's trade union affiliation or activities, classified as a special category of personal data under GDPR Article 9 due to historical discrimination risks and political sensitivity. This includes formal membership records, dues payments, union representative roles, participation in union activities, and information from which union membership can be inferred. Processing trade union data is generally prohibited unless specific conditions are met: explicit consent, processing necessary for employment/social security law, vital interests protection, legitimate activities of trade unions themselves (with appropriate safeguards), data made manifestly public by the data subject, legal claims, substantial public interest, or social care purposes. Employers processing employee union data must be particularly careful—employment contexts may involve power imbalances affecting consent validity, and using union membership in employment decisions could constitute illegal discrimination. Organizations should: minimize collection and use of union-related data, implement heightened security controls, carefully document legal bases, conduct Data Protection Impact Assessments, and ensure processing doesn't discriminate against union members.