1) Prevent Unauthorized Transactions in your demat account --> Update your Mobile Number with your Depository Participant. Receive alerts on your Registered Mobile for all debit and other important transactions in your demat account directly from NSDL/CDSL on the same Day......................issued in the interest of investors.
2) No need to issue cheques by investors while subscribing to IPO. Just write the bank account n umber and sign in the application form to authorize your bank to make payment in case of allotment. No worries for refund as the money remain in investor's account
3) KYC is one time exercise while dealing in securities markets - once KYC is done through a SEBI registered intermediary (broker, DP, Mutual Fund etc.), you need not undergo the same process again when you approach another intermediary.