(5)Not all investment firms use International Financial Reporting Standards and there are differences in the applicable accounting standards in the calculation of the total costs. Elements to be deducted by investment firms from their total expenses used for the calculation of the fixed overheads requirement should be further specified, in addition to those provided in Article 13(4) of Regulation (EU) 2019/2033, in order to ensure comparability in the calculation of the fixed overheads requirement.