There is concept introduced in Demat called the transposition of shares. Transposition means that if the shares are held in the name of A & B and customer has a demat account in the reverse order i.e. name of B & A - the shares can be dematerialised in the same account, and a new demat account in the name of B and A would not be required. The client has to submit the shares and the demat request form along with transposition form. You may get the transposition form from the portal.