A method and system for performing financial transactions. The method includes receiving by a mobile device, credit/debit card data belonging to a user of the mobile device. The credit/debit card data is registered with a financial transaction server and the user is authenticated. A USSD message comprising details associated with the user and a financial transaction is transmitted to a USSD server and a financial transaction server. In response, a random code representing the user and the credit/debit card data is received by the mobile device and a barcode is generated based on the random code. The bar code is presented to a merchant barcode scanner. The barcode is scanned, decoded, and transmitted to the financial transaction server. The decoded barcode is compared to the random code to perform a verification process associated with the financial transaction, the user, and credit/debit card data.