1.

Article 5 of Council Directive 93/13/EEC of 5 April 1993 on unfair terms in consumer contracts and the requirement of transparency of contractual terms in the context of a mortgage loan must be interpreted as allowing the seller or supplier not to include in such a contract the full definition of the reference index used to calculate a variable interest rate or not to provide to the consumer an information booklet setting out past fluctuations in that index prior to signature of that contract, on the basis that the information related to that index has been officially published, provided that, in the light of publicly available and accessible information, as well as the information provided, where appropriate, by the seller or supplier, an average consumer who is reasonably well informed and reasonably observant and circumspect was able to understand the specific functioning of the method used for calculating the reference index and thus evaluate, on the basis of clear, intelligible criteria, the potentially significant economic consequences of such a term on his or her financial obligations.

2.

Article 3(1), Article 4(2) and Article 5 of Directive 93/13 must be interpreted as meaning that, where a national court takes the view that a contractual term the purpose of which is to determine the method for calculating a variable interest rate under a mortgage contract is not drafted in plain intelligible language within the meaning of Article 4(2) or Article 5 of that directive, that court is required to examine whether that term is ‘unfair’ within the meaning of Article 3(1) of that directive.

3.

Article 6(1) of Directive 93/13 must be interpreted as requiring the national court to offer the consumer a choice between, on the one hand, amending the contract by substituting a contractual term fixing a variable rate of interest found to be unfair with a term referring to a supplementary index provided for by law, and, on the other hand, annulment of the mortgage loan agreement in its entirety if that contract is not capable of continuing in existence without that term.

4.

Article 6(1) and Article 7(1) of Directive 93/13, read in the light of Article 1(2) of that directive, must be interpreted as not precluding the national court, where an unfair term setting a reference index for calculating the variable interest of a loan is null and void, from replacing that index with a statutory index applicable in the absence of an agreement to the contrary between the parties to the contract, in accordance with the conditions laid down in paragraph 67 of the judgment of 3 March 2020, Gómez del Moral Guasch (C-125/18, EU:C:2020:138), where those two indices are determined by a method of calculation of equivalent complexity and national law provides for that replacement to be made where there is no dispute and the objective is to preserve the balance of the parties’ obligations, provided that the substitute index does in fact reflect a supplementary provision of national law.

5.

Article 6(1) of Directive 93/13 must be interpreted as meaning that, where a contract concluded between a seller or supplier and a consumer is not capable of continuing in existence after the removal of an unfair term and the annulment of the contract in its entirety would expose the consumer to particularly unfavourable consequences, the national court may cure the invalidity of that term by substituting it with a supplementary provision of national law, with the application of the rate resulting from the substitute index taking effect at the date of the conclusion of the contract.