Can I add another person as a joint holder to my account?
No, you will not be able to add another person as a joint holder to your existing account with Zerodha.
You will have to close your existing residential individual account and open a new account as a joint account. In such a case, your existing shares from your Resident individual account will be transferred to your joint account with the Zerodha account.
To know more about the joint account opening, click here.