Required if consent serve as legal justification.
Shall be unambiguous or even explicit￤New.
Proof of consent is an important element, by which accountability is to be demonstrated (forms, records, compulsory statements).
Consent for new purpose raises complexity.
Legal justification based on consent is challenged by individual’s rights (withdraw, portability, erasure).
Lawful if child is at least 16, member states may rule for younger age (13 minimum).
Under 16 years of age (13), parental authorization is required.