MMID stands for Mobile Money Identifier. It is a seven-digit number provided by banks to their customers to enable them send money through Immediate Payment Service (IMPS). It allows real-time inter-bank electronic fund transfer using mobile phones.
MMID number is required when someone wants to send or receive money through IMPS. Each bank account has a unique MMID number, for example, if you have two bank accounts in two different banks or the same bank, you will have two different MMID numbers. Furthermore, one mobile number can be linked to different MMIDs.
MMID is not provided when you open a bank account. You are required to apply for the MMID number if you need it. Different banks have different ways to provide this number such as some banks allow you to generate this number by sending an SMS, some allow through net banking or mobile banking, and some provide in the mobile banking kit. If you have an MMID number and phone number of a person you can send money even if you don't have his account number and ifsc code.