(5)To ensure the safety and security of payment service users’ data, payment service providers should, at any time, be allowed to apply strong customer authentication where they have objectively justified and duly evidenced reasons relating to unauthorised or fraudulent access. This might be the case where the transaction monitoring mechanisms of the account servicing payment service provider detect an elevated risk of unauthorised or fraudulent access. In order to ensure a consistent application of the exemption, account servicing payment service providers should in such cases document and duly justify to their national competent authority, upon its request, the reasons for applying strong customer authentication.