By virtue of Article 23 of Regulation No 1/2003, the maximum amount of the fine is set, for each undertaking or association of undertakings participating in the offense, at 10% of the total turnover achieved in the preceding business year. The rule for taking into consideration the turnover of the last business year prior to the adoption of the decision is not mandatory and the possibility for the Commission to derogate from it is not limited to “exceptional cases”. The Commission may therefore depart from this rule when the last financial year preceding its decision is not relevant to the situation of the undertaking, in particular when the latter transferred the subsidiary in question and abandoned any operational activity to become a mere holding company managing its equity shortly after the infringement ended. On the other hand, there is no reason to set aside the application of the general rule due solely to the fact that the turnover for the year preceding the decision would be artificially high due to a significant increase in the price of the raw material and the takeover of the business activity by a third party undertaking or internal restructuring having taken place between the end of the infringement and the date of the decision. The choice made by the EU legislature to take the turnover figures for the last full business year preceding the adoption of the decision setting the amount of the fine as the reference value as the most likely to reflect the financial capacity of an undertaking also justifies referring to the average exchange rate applicable at that time to convert that turnover, where it is expressed in a currency other than the euro.

When several companies form a single undertaking within the meaning of Article 101 TFEU, the 10% ceiling must be calculated on the basis of their combined turnover. The Commission is not required to demonstrate that each subsidiary making up the group has no autonomy to determine its behavior on the market to take account of its consolidated turnover in calculating the ceiling of the fine. Similarly the fact that some of the undertakings forming the single economic entity found guilty of the infringement were not active on the same market is irrelevant to the determination of the turnover to be taken into account for the calculation of the fine. In contrast, when the economic entity which existed at the date of the implementation of the infringement was broken up at the time the Commission adopts its decision, the ceiling of the fine must be calculated individually for each of its constituents. In the event of a restructuring, where there are two distinct periods – the subsidiary is held liable for the infringement for the period prior to its acquisition, and the parent company is held jointly and severally liable with the subsidiary for the period after the acquisition,- the Commission must apply the 10% ceiling individually without applying it to all the companies of the group in its composition on the date the decision is adopted. Where the Commission sanctions two separate infringements, it is free to impose two fines, the combined amount of which can exceed the 10% ceiling.

Where the infringement of an association relates to the activity of its members, the fine cannot exceed 10% of the sum of the total turnover achieved by each member active on the market concerned. The final amount of fine must not exceed that 10% limit but the intermediary amount at the various steps of the calculation may be higher. The prohibition on exceeding the legal ceiling does not require the Commission to take account of the amount imposed on the undertaking in a previous decision concerning different infringements.