Zerodha users can add or link their family members' account with their account. Here is the process;
Login to Zerodha Kite>Dashboard>Holdings>family.
Click on “link a Sub-account”.
Fill in the required details such as sub-accounts Kite user ID, PAN, and mobile number.
Click on “Continue”.
Then the sub-account holder will receive a verification SMS on his mobile number and he has to authorize it by clicking on the verification link. The link expires after 2 hours, if missed you have to reinitiate it again.