A UPI ID is a virtual payment address (VPA) for every UPI user. Every user is required to generate a UPI ID in order to access the UPI services. The UPI ID acts as a way for the banks to track the user’s account.
A UPI ID is written in the following format abcd@bank (where, ‘abcd’ can either be your first name, a part of your email address, or your mobile phone number, and bank is the name/initials/shortened name of the bank – providing services to the UPI app – with some prefix or suffix added in some cases).

Example:
For example: nouser-232@okhdfcbank, janedoe-11@paytm