BHIM

BHIM (Bharat Interface for Money) is an Indian mobile payment App developed by the National Payments Corporation of India (NPCI), based on the Unified Payments Interface (UPI). Named after B. R. Ambedkar and launched on 30 December 2016, it is intended to facilitate e-payments directly through banks and encourage cashless transactions.
The application supports all Indian banks which use UPI, which is built over the Immediate Payment Service (IMPS) infrastructure and allows the user to instantly transfer money between bank accounts of any two parties. It can be used on all mobile devices.
Operation.
BHIM allow users to send or receive money to or from UPI payment addresses, or to non-UPI based accounts (by scanning a QR code with account number and IFSC code or MMID (Mobile Money Identifier) Code).
Unlike mobile wallets (PayTM, MobiKwik, mPesa, Airtel Money, etc.) which hold money, the BHIM app is only a mechanism which transfers money between different bank accounts. Transactions on BHIM are nearly instantaneous and can be done 24/7 including weekends and bank holidays.
Version 1.3 allows users to use mobile numbers from their contact book to send money and also save payment addresses for future use . It now also allows users to send or receive digital payments through Aadhaar authentication.
Transaction fees and limits.
Currently, there is no charge for transactions from ₹1 to ₹100,000. Some banks might, however, levy a fee for UPI or IMPS transfers.
In 2020 Indian banks have proposed transaction charges on UPI transactions, but there is no information on whether transactions through BHIM will also be charged.
Language support.
The app currently supports 20 languages (including English), and is expected to support all 22 recognised languages of India 
Reception.
During the 2017 Union budget of India, Finance Minister Arun Jaitley said that the app is currently being used by over 12.5 million Indian citizens, and that the government will launch two new schemes to promote its use. One will be referral payments for individuals, and the other will be cashback for merchants who accept payments .
Security.
In May 2020, VPNMentor, a cyber security firm disclosed that BHIM app has suffered a huge data breach leaking approximately 7.26 million Indian users personal and financial data, such as name, contact details, Aadhaar card, PAN card, caste certificate, fingerprint scans, educational certificates and more. The 4.09 GB files were leaked from a CSC operated website because of misconfigured AWS S3 bucket, and not the official BHIM website. But CSC explicitly mentions that it is working with BHIM and NCPI in partnership. VPNMentor and other cybersecurity experts confirm the data to be authentic, but BHIM and NCPI claim that the breach never took place. The issue has now been fixed.