On 18 September 2013, the Paris Court of Appeal confirmed case law pertaining to the nature of services to be provided by auditing firms in the area of reducing social costs. For this court, this type of mission "itself constitutes a legal service" and should be considered as a legal consultation. However, this type of consultation is located within the legal perimeter reserved for regulated professions. 

Consequently, this ruling and the previous rulings imply three legal consequences: (1) the audit agreement is illicit and consequently it is proven that its underlying practices provide a genuine method of working (and not a simple verification of the state of applicable law); (2) beyond this idea of illicitness, the audit agreement itself is declared invalid, in its content and cause, whatever the gravity and circumstances of the irregularity; (3) the invalidity of the agreement implies the return of the amount for the service, the amount corresponding to the lowest of the two amounts between gain for the client and impoverishing the service provider.