People should be able to transfer money to me using any unique ID I have, such as a PAN card number, passport number, or email ID . There should be a central repository where I claim my PAN card number, passport number, mail IDs and other unique IDs, and map them to my real bank account details, such as the account number and the bank . Then, when someone wants to transfer money to me, they can say, for example, “Please transfer ₹500 to PAN card xxxxxx”, and have the system figure out the details.
If I have multiple bank accounts, I should be able to set one as the default recipient.
This should work for the post as well — you shouldn’t have to write a long-winded, imprecise address on envelopes. Just identify the recipient by their mail ID or PAN card number or whatever ID you have about them, and the post will reach them.
Payments and shipping should be simplified.
 Not phone numbers, since they do get reassigned over time.
 Account numbers should be unique across banks, so there should be no need for a bank name, branch and IFSC code. If you owe me money, and I tell you that my account number is 1234, you should be able to transfer money to 1234 without any more information needed. Perhaps we can use the country code from the phone system to identify the country, like +91 1234 for an account 1234 held in India. Just as phone numbers don’t need to be qualified by the carrier, neither should bank account numbers.