(12)In calculating the annual supervisory fee, subsidiaries established in non-participating Member States should not be taken into account. In this respect, and in order to determine the relevant fee factors of a supervised group, sub-consolidated data for all subsidiaries and operations controlled by the parent undertaking in the participating Member States should be provided. However, the costs of producing such sub-consolidated data may be high and, for this reason, supervised entities should be able to opt for a fee calculated on the basis of data provided at the highest level of consolidation within the participating Member States including subsidiaries established in non-participating Member States, even if this might result in a higher fee.