The Sentence of the Court of Justice of the European Union of July 16, 2020 comes to answer the fifteen questions that, in its preliminary rulings, were posed by two Courts of Instance of Mallorca and Ceuta, grouped into four main thematic categories on matter. In this long-awaited resolution, the CJEU clearly rules against the interests of financial entities, providing in general the necessary return of expenses declared abusive and unduly charged to consumer borrowers, unless the national law provides otherwise. Thus, with the exception of the Tax on Documented Legal Acts, banks must return the expenses derived from the clauses that were once declared unfair. In addition, the ruling opens the possibility of declaring the controversial opening commissions abusive. In this sense, the ruling of this resolution, which resolves the issue regarding a mortgage contract signed with Caixabank in 2000 and another contracted with BBVA in 2011, establishes that national judges are competent to declare the opening clauses unfair, By virtue of which the bank has been allowed to charge clients a commission for the mere opening of the credit, but without offering the consideration of a service in exchange. In this regard, the CJEU considers that, despite the fact that this amount is part of the total payment of the loan, it is not a main or essential clause of the agreement, but an accessory stipulation and, as such, its possible abusiveness may be considered by a national judicial body, regardless of whether Spain has not transposed Article 4, paragraph 2, of the Directive into its legal system. The CJEU resolution is final by establishing that the imposition of this opening commission on the consumer is detrimental and is an act contrary to good faith, unless the entity demonstrates that a service is being provided in exchange, an aspect that must be determined by the national judge, meaning that Spanish law already provided that a service must be provided for all charges. The CJEU points out in this regard that any clause that exempts the professional from proving that these services have been provided may cause an imbalance between the parties, and therefore the judges have the competence to also declare them void. In the same resolution, the CJEU addresses the issue of the statute of limitations for the restitution action, and the imposition on the consumer of part of the procedural costs based on the amount of the amounts unduly paid, allowing the costs to be imposed on the banking entities. Almost immediately after the decision of the Luxembourg Court, the Judgment of the First Civil Chamber of the Supreme Court no. 457/2020, of July 24, applies the doctrine established in the STJUE of July 16, 2020.