(4)To ensure the accuracy of the financial information needed to calculate the applicable turnover, all figures provided by the ICT third-party service providers should be audited. Considering that information on the applicable turnover is necessary for the Lead Overseer to establish the amount of the oversight fee charged to each critical ICT third-party service provider yearly to cover the costs of the oversight, the Lead Overseer should consider the worldwide revenues of ICT third-party service provider generated irrespective of the types of clients in the case where the critical ICT third-party service provider does not provide for tailored information on the revenues generated in the Union from the provision of the ICT services to financial entities.