(25)To ensure legal certainty and a level playing field among selected obliged entities, any selected obliged entity should remain under the direct supervision of the Authority for at least three years, even if, after the moment of selection and in the course of those three years, the selected obliged entity ceases to meet any of the cross-border activity or risk-related criteria due to, for example, a potential ceasing, consolidation, expansion or re-allocation of activities carried out through establishments or under the freedom to provide services. The Authority should also ensure that sufficient time is allocated to the preparation by the selected obliged entities and their supervisory authorities for the transfer of supervision from national to Union level. Therefore, each subsequent selection should commence 12 months before the expiry of the three-year period of supervision of the previously selected obliged entities.