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. The service is available 24×7 throughout the year including bank holidays. NEFT was also made available 24×7 from December 2019.RTGS was also made available 24×7 from 14 December 2020.
Unified Payments Interface is built on top of IMPS, with the key architectural work done by the Mobile Payments Forum of India, IIT Madras and IDRBT.
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 22 November 2010. As of April 2023, there are 722 member banks which signed up for the IMPS service. Around 200 million IMPS transactions amounting to roughly US$20 billion 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.