The Court held that in the absence of harmonisation of the national mechanisms for recovery of uncontested claims, the rules implementing national order for payme
nt procedures are a matter for the national legal order, in accordance with the principle of the procedural aut
onomy of the Member States, on condition, however, that they are no less favourable than those governing similar domestic actions (principle
...[+++]of equivalence) and do not make it in practice impossible or excessively difficult to exercise the rights conferred on consumers by European Union law (principle of effectiveness).