The most important component in a payment system is a payment instrument that is useful to support the system to keep it running. The payment system includes payment instruments that are legal to use, and other banking procedures used in the payment process. Money is defined as a means of payment/purchase of goods and services that have a function as a unit of account that shows the value of an item or service that is sold or purchased. The Government of Indonesia through the Central Bank in order to fulfill the people's need for money, creates currency in the form of coins and banknotes and does not only arrive at currency. With the development of technology, demand deposits are issued by commercial banks in the form of checks, bilyet giro, and credit. cards. Even in its development in Indonesia, e-money (electronic money) has also emerged which has been recognized by the Indonesian government.
Electronic money can be said to be a legal payment instrument if it meets the requirements, namely being circulated based on the amount of money deposited in the form of rupiah, so that if these criteria have been met and based on mutual agreement, the money to be circulated can be used by the public. Bitcoin is not the same as electronic money because it continues to be produced through a mining process so that it does not meet the requirements of electronic money. The presence of bitcoin as a virtual currency raises questions about its legality in Indonesian law, some people think that Bitcoin is a new innovation in terms of the economy, especially in the field of trade in goods and services that serve as a means of payment for its users and besides that bitcoin can be an investment destination. Currency is money issued by the Unitary State of the Republic of Indonesia, hereinafter referred to as Rupiah and emphasized in Article 2 of the Currency Law which states that money is a legal tender and Indonesia recognizes rupiah as the currency in force in its territory. Rupiah is the currency that must be used in every transaction that has the purpose of payment, obligations that must be met with money or other financial transactions in Indonesia, because if there is a payment without using rupiah, it can be punished. However, there are exceptions that the use of rupiah is not mandatory in the case of certain transactions in the context of implementing the state budget of revenues and expenditures, receiving or granting grants from or to foreign countries, international trade transactions, deposits in banks in the form of foreign currencies, or international financing transactions. Based on the legal material collected, bitcoin transactions in the community can still be used or have legality as long as they follow the applicable rules.