(10)Both the power to impose fines and periodic penalty payments and the power to enforce fines and periodic penalties should be exercised within a reasonable time, and should therefore be subject to a limitation period. For reasons of consistency, limitation periods for the imposition and enforcement of fines or periodic penalty payments should take into account existing Union legislation applicable to the imposition and enforcement of penalties on supervised entities and ESMA’s experience in applying such legislation. In order for ESMA to ensure safekeeping of collected fines and periodic penalties, ESMA should deposit them on interest-bearing accounts that are opened exclusively for the purpose of a single fine or periodic penalty payments aiming at ending a single infringement. As a matter of budgetary prudence, ESMA should only transfer the amounts to the Commission once the decisions are final due to the rights to appeal being exhausted or lapsed.