(13)Fees charged by the registers for online procedures should be calculated on the basis of the costs of the services in question. Such fees could also cover, inter alia , the costs of minor services performed without charge. In calculating their amount, Member States should be entitled to take account of all the costs related to carrying out the online procedures, including the proportion of the overheads which can be attributed thereto. Furthermore, Member States should be allowed to impose flat-rate charges and fix the amount of such charges for an indefinite period, provided that they check at regular intervals that such charges continue not to exceed the average cost of the services in question. Any fees for online procedures charged by the register in the Member States should not exceed the recovery cost of providing such services. Moreover, where the completion of the procedure requires a payment, it should be possible that the payment can be made by means of widely available cross-border payment services, such as credit cards and bank transfers.