(7)National competent authorities incur costs when assisting ESMA in its supervisory tasks and, in particular when those national competent authorities assist ESMA pursuant to Article 55(4) and Article 56(5) of Regulation (EU) 2023/2631. The fees ESMA charges external reviewers of European Green Bonds should therefore also cover those costs. To avoid national competent authorities incurring a loss or profit from carrying out delegated tasks or from assisting ESMA, ESMA should reimburse only the actual costs incurred by that national competent authority.