The main purpose of transactions through development is to send and receive money from one place to another. In mobile banking terms it is called send money and cash out. In other words, it can be called an easy alternative to the money order of the postal department. In order to get the service, first you need to go to the agents of the company (representative) and open an account by filling up the prescribed form. If you are working then there is nothing fundamentally against Sharia till now. A mobile account holder can send a fixed amount of money from his account to another account holder. This is called send money. This facility is offered at the prescribed flat rate. There is no legal problem in this too. Cash out. This is the most widely used feature of mobile banking. Withdrawals from one's own account or remittance to an agent are most common through mobile banking (bKash , mCash, etc.). Leasing is the name given to selling a service for a fixed price. (See also: Al-Awsat 11/131 ; Almugani 7/22 ; Al- Furuk 4/34) And the company is the service provider or 'Azir'. The agent is the lawyer or representative of the main service provider or 'Azire'. In case of Wakalah or Agency Contract , the Agent or Representative may perform the duties of his Agency in return for remuneration . And in the case of remuneration, it is important to be specific. It can be a specific number or a fixed rate of a number - both. For example, 10 rupees for 100 rupees , or 10% of 100 rupees - both are valid. So here your brother can take a fixed rate or commission as the agent of the main service provider company. It will be valid for him. However, in this case , Although there is no problem in sending and receiving money through development as a whole , it should be noted that it is not a co-operation in the interest-based activities of the interest - based organization . Money should not be stored for long. This is because they will have the opportunity to invest the customer's money in the interest-based sector for a while.