Mobile banking is a type of banking service that can be accessed directly via mobile phone networks such as GSM (Global System for Mobile Communication) or CDMA (Code Division Multiple Access) by using data services that have been provided by mobile phone operators. Lately increasingly popular mobile banking is used by society because it is easy to use specially to conduct transactions electronically. Transactions conducted via mobile banking can be done in real time so the consumers don’t have to bother coming to the ATM or bank to conduct financial transactions as well as non-financial transaction. But although it has features which facilitates consumers in conducting financial and non-financial transactions in real time, mobile banking has its own security system defect, which can be exploited by hackers to steal some money from victims’ bank account. There are several ways for hackers to compromise consumers-owned mobile banking. Firstly, they can compromise mobile banking system directly by simply hacking it. Secondly, they can perform a phishing scam to collect customers’ data. Thirdly, they can perform a SIM swap to access Customers’ bank account from their phone. The purpose is to obtain personal information of consumers that can be used to access consumers’ bank account. As the result, consumers suffer material and immaterial loss. Thus, the legal protection in the use of mobile banking application by BNI has the role to protect consumers in conducting transactions electronically. BNI can protect the consumers’ rights by providing clear information about the use of BNI mobile banking application and make the terms and conditions which ensure consumers' rights are protected in conducting transactions through BNI mobile banking application as well as accommodate and resolve customers’ complaints systematically based on the regulation of the financial services authority regarding consumer protection.