The processing of personal data revealing trade union membership is in principle prohibited. A person's membership can be inferred from membership fees and other membership obligations made to your organisation. As soon as a consumer makes use of a PSD2 account information service provider, this membership can be disclosed. The PSD2 does not offer the possibility to prevent this. Do you know what a PSD2 provider or profiling company can do with this information?
Maybe you don't mind. The consumer gives his or her own consent, right? As an organization you have a special responsibility to protect the personal data of your members or interested parties. By including your member account(s) in the register, you protect your supporters and offer them better protection of their privacy.