In case of financial transaction without authorization, the liability of financial institutes which executed the transaction is a hot issue. According to the Electronic Financial Transaction Act(EFTA) which was promulgated last April, financial Institutes and electronic financial service provider shall be liable to the user of the services for damages due to using the forged access tool or some accidents during transmission of payment order. When the user of electronic financial service and electronic financial service provider(including financial institutes) have acted in good faith and without negligence in electronic financial transaction, EFTA charges the liability for the loss on electronic financial service provider in principle, which, I think, contradicts to the general rule of negligence liability and Civil Code. If a mandatary, without any negligence on his part, sustains damages through the management of the entrusted affairs, he may demand compensation therefor from the mandator(§688 of Civil Code). As the contract between the user of electronic financial service and electronic financial service provider is construed as mandate contract and the latter is mandatory, in case that the latter is without any negligence on his part, damages through the management of the entrusted affairs like electronic financial transactions should be charged on the mandator, the user of electronic financial service. Though EFTA can change the rule of civil code from the view point of consumer protection, the allotment of liability to both parties is necessary, like EFTA(Electronic Fund Transfer Act) or UCC 4A of US.