For HDFC  Bank Account holders :

Following is the link and the steps to update POA.

Link  :https://allinone.hdfcsec.com/login

       Step 1. Enter cust registered mobile number.

       Step 2. Enter the OTP received.

       Step 3. Download the Power of Attorney.

       Step 4. Sign the POA copy to the address mentioned in it or to the nearest HDFC securities Branch.

For Non HDFC  Bank Account holders :

In order to enjoy uninterrupted Margin Trading Facility guide the cust to open  HDFC Bank Account with POA linked to the resp. HDFC Securities Trading Account before May 4, 2022.