Judgment_paragraph 43 · Profi Credit Bulgaria v T.I.T (C-170/21)

43In that context, the Court has found that it is for the Member States, by means of their national legislation, to define the detailed rules under which the unfairness of a contractual clause is established and the actual legal effects of that finding are produced. However, that finding must allow the restoration of the legal and factual situation that the consumer concerned would have been in if that unfair term had not existed, by, inter alia, creating a right to restitution of advantages wrongly obtained, to the consumer’s detriment, by the seller or supplier concerned on the basis of that unfair term. Such regulation by national law of the protection guaranteed to consumers by Directive 93/13 may not adversely affect the substance of that protection (see, to that effect, judgment of 21 December 2016, Gutiérrez Naranjo and Others, C‑154/15, C‑307/15 and C‑308/15, EU:C:2016:980, paragraphs 65 and 66).