DP charges include Depository charges and Depository Participant (DP) charges. The Depositories are NSDL & CDSL and Depository participants are members of Depositories with whom you open your demat account (Eg: IL&FS). DP charges are applicable whenever you sell any shares from your demat account. This charge is a source of revenue to the Depositories & its participants. Similar to how Exchanges charge Transaction fee, Brokers charge brokerage, Depositories & DP’s charge DP charge.
NSDL charges a depository fee of Rs.4.50 per debit transaction. The Participant charge would vary depending on where you’ve opened your demat account but is normally a flat fee per sale transaction.