Tahdonilmaisunsa

Tahdonilmaisunsa is a Finnish term referring to a person’s expression of will or consent in legal and practical contexts. It denotes the act by which someone agrees to a proposed action, such as entering a contract, undergoing medical treatment, permitting data processing, or participating in research. The concept is central to Finnish contract law, medical ethics, and data protection frameworks, and it is often discussed together with the related idea of consent (tahdon).

In Finnish law, a valid tahdonilmaisunsa must be freely given, specific, informed, and an unambiguous indication of the person’s wishes. This aligns with broader European standards for consent, including the principle that consent should be an active choice rather than a passive silence. Consent can be expressed in writing, orally, or electronically, as long as there is reliable evidence of the person’s will. For processes governed by data protection rules, consent is one of several lawful bases for processing personal data, and explicit or specific consent is required for handling certain sensitive information.

Withdrawal and revocation are key features: a person may revoke their tahdonilmaisunsa at any time, and withdrawal does not retroactively invalidate actions performed while consent was valid, provided those actions complied with applicable law at the time. Special rules apply for individuals who lack capacity, such as minors or those with cognitive impairments, where guardians or legal representatives may consent on their behalf.

Tahdonilmaisunsa is thus a foundational concept in Finnish law for validating voluntary agreement, shaping rights and responsibilities across contracts, healthcare, and privacy protections.