Immediate Payment Service (IMPS) is an instant payment inter-bank electronic funds transfer system in India. IMPS offers an inter-bank electronic fund transfer service through mobile phones. Unlike NEFT and RTGS, the service is available 24/7 throughout the year including bank holidays.
It is managed by the National Payments Corporation of India (NPCI) and is built upon the existing National Financial Switch network. In 2010, the NPCI initially carried out a pilot for the mobile payment system with 4 member banks (State Bank of India, Bank of India, Union Bank of India and ICICI Bank), and expanded it to include Yes Bank, Axis Bank and HDFC Bank later that year. IMPS was publicly launched on November 22, 2010. Currently, there are 53 commercial banks, 101 Rural/District/Urban and cooperative banks, and 24 PPIi signed up for the IMPS service. 
Around 200 million IMPS transactions amounting to roughly 20 billion dollars of transaction amount happen every month in India. The sender requires to know the bank account number and the Indian Financial System Code of the beneficiary to transfer money.