ISO 20022 is an international messaging standard that simplifies global business communication by creating a common language for financial information. DTC uses ISO 20022 real-time MQ messaging and files for automated electronic communication with clients. The ISO 20022 standard provides a modernized business model and platform that replaces legacy proprietary formats and files.

Corporate Actions Messaging Specifications for ISO 20022 are intended as an implementation overview for both technical and business experts. DTCC uses the ISO 20022 Corporate Actions Message format for its Corporate Actions Announcements, Entitlements and Allocations, Instructions and Meetings data. 

SR Release Files

Standard Release (SR) message types in .zip archives:

• Business Application Header
• Announcements 
• Entitlements and Allocations
• Elective Dividend Instructions
• Voluntary Reorganization Instructions
• Meeting Proxy

DTCC provides messaging specifications for the standard ISO 20022 message and when applicable, its proprietary Extension component. 

The specification zip files contain the following folders, when applicable:

• Message Usage Guidelines in Excel format.
  These documents present the logical layout of the message XML schema. There are separate documents for each XML schema -- one for ISO ‘core’ standard message, and one for supplementary data (extension) that embeds in the standard message. The document shows the elements that will be used in the message; elements that will not be used are marked as “removed”. The document also contains DTCC market practice usage for each element e.g. DTCC definitions, annotations, rules, as well as DTCC synonyms that are the DTCC names of the elements used in browser and Data Dictionary.
• Message Usage Guidelines in .pdf format. 
  Similar to the Excel document, the PDF version provides an alternative format showing the message structure, message building blocks, message components, message data types and restrictions summarization.
• DTCC extension schemas.
  Plain XML schema for DTCC extensions.
• ISO 20022 unrestricted schemas.

ISO 20022 messages undergo annual change maintenance each November via a “Standards Release” or “SR”. Note: There are multiple message types within each of the four message categories in the table below.

 Please download and unzip the files. 

Data Dictionaries

 This collection of documents provides detailed mappings of event types to function / activity codes.

Meetings – SR 2021

•  Corporate Action Meetings Data Dictionary SR 2021 (Updated May 11, 2021) – This document outlines mapping for tags associated with ISO 20022 published data fields for Meetings messages.

Announcements, Entitlements & Allocations, and Instructions – SR 2025

•  Corporate Action Announcements Data Dictionary SR 2025 (Updated July 21, 2025) – These documents list the ISO 20022 event types, as well as the ISO 20022 published data fields and mapping back to DTC function codes.
•  Corporate Action Entitlements and Allocations Data Dictionary SR 2025 (Updated May 30, 2025) – These documents list the ISO 20022 event types, as well as the ISO 20022 published data fields and mapping back to DTC function codes.
•  Corporate Action Elections Data Dictionary SR 2025 (Updated October 15, 2025) – These documents outline mapping for tags associated with ISO 20022 messages for Distributions Instructions to data elements associated with DTC's EDS legacy process, as well as Reorganization Instructions mapping.

Announcements, Entitlements & Allocations, and Instructions – SR 2026

•  Corporate Action Announcements Data Dictionary SR 2026 (Updated July 31, 2026) – These documents list the ISO 20022 event types, as well as the ISO 20022 published data fields and mapping back to DTC function codes.
•  Corporate Action Entitlements and Allocations Data Dictionary SR 2026 (Updated July 31, 2026) – These documents list the ISO 20022 event types, as well as the ISO 20022 published data fields and mapping back to DTC function codes.
•  Corporate Action Elections Data Dictionary SR 2026 (Updated July 31, 2026) – These documents outline mapping for tags associated with ISO 20022 messages for Distributions Instructions to data elements associated with DTC's EDS legacy process, as well as Reorganization Instructions mapping.

ISO 20022 Messaging User Guides

•  Getting Started - Announcements & Data Model
• Lifecycle: 
  •  Distributions (Entitlements and Allocations)
  •  Redemptions (Entitlements and Allocations)
  •  Reorganizations (Entitlements and Allocations)
• Instructions:
  •  Distributions
  •  Reorganizations

 The information and links above are provided for your convenience. For additional ISO 20022 Messaging resources, see the ISO 20022 Messaging Resources tab.