CDSL Extended

CDSL (Central Depository Services Limited) is one of India’s two securities depositories, responsible for holding securities in electronic form and facilitating their transfer. The core CDSL integration — opening a BO (Beneficiary Owner) account during onboarding — is documented in the main vendor integration spec. This page serves as an index to the extended CDSL deep-dive guides that cover post-onboarding operations: DDPI (Demat Debit and Pledge Instruction) lifecycle, margin pledge operations, account modifications, and the technical integration guide for UAT (User Acceptance Testing) and production environments.

You will need these guides when working on features beyond initial account opening — things like enabling DDPI for a customer, handling an address change, or debugging a pledge file rejection.

Deep-Dive Guides

DDPI Deep Dive

DDPI lifecycle covering:

Regulatory background and SEBI (Securities and Exchange Board of India) circulars
Four authorization types (settlement, pledge, MF, open offer)
DDPI vs POA (Power of Attorney) detailed comparison
Technical implementation — POA_TYPE_FLAG, BO Modify file format
Online submission flow with eSign integration
Revocation and modification process
Trading flow with vs without DDPI
Stamp duty by state and processing timelines

MTF & Pledge Operations

Margin pledge, re-pledge, MTF (Margin Trading Facility) funding, and eLAS covering:

Pledge ecosystem architecture (Client to TM/CM to CC)
Three types of pledges: Normal, Margin, MTF
Client-to-broker pledge and broker-to-CC re-pledge flows
MTF pledge process (T+3 acceptance deadline)
Tag-based file format with sample pledge/unpledge/invocation files
SEBI automated pledge mechanism (Oct 2025)
Haircut framework and margin benefit calculations
CUSPA and MTF-specific demat accounts
Pledge cost structure

BO Modifications

Comprehensive BO account modification use cases:

Address change with auto-propagation
Bank account modification (penny drop, min/max rules)
Nominee update (10 nominees since Jan 2025, percentage allocation)
Nomination opt-out with video verification
Simplified transmission on death of holder
Email / mobile update (6-attribute KYC sync)
PAN correction process
Segment activation / deactivation
BO account closure and dormancy reactivation
Modification summary matrix

Integration Guide

Technical integration and regulatory reference:

UAT vs production environment endpoints
UAT certification process (5-phase, 6-10 weeks)
CDSL Innovation Sandbox
Request tracking and unique sequence numbers
File naming conventions (DP57, DPM3, DP97)
File upload acknowledgment and status polling
Multi-layered security architecture (5 layers)
DSC (Digital Signature Certificate) management
eDIS encryption details
IP whitelisting requirements
Connectivity security comparison
SEBI circulars reference (DDPI, pledge, nomination)
CDSL communiques index

Source Documents

The extended CDSL specifications are maintained in:

vendors/depositories/CDSL.md — Sections 23-29 (source for deep-dive guides)
CDSL_INTEGRATION.md — Original deep-dive specification (v1.3)