Method of delivering a franking service including the following operations: connection via a communications network of a user's communications device (10, 12) with a server system (18) operated by a franking services provider, entry via the communications device of a unique identification number carried by a mail item (14) to be sent, selection by the user of a franking service from the various franking services offered by the server system and entry of postal information in relation to the selected service, determination by the server system on the basis of this information of the cost of the selected franking service and communication of this cost to the user, payment by the user for the selected franking service, and depositing of the mail item in a post box (16).