ISO 20022 corporate actions in practice

What actually changes, and how to prepare without disrupting operations

ISO 20022 is steadily becoming the new standard for financial messaging across the industry. While much of the early focus was on payments and pricing, corporate actions are now entering the same transition. ISO 20022 corporate actions are becoming an increasingly important topic for organisations that still rely on MT 564 for daily processing.

In payments and pricing, timelines were fixed and options were limited. Corporate actions, still largely driven by MT 564, are now entering a similar transition, but with less regulatory pressure and greater operational complexity. MT 564 is a SWIFT message type, distributed via the SWIFT network. While technically a single message, it effectively represents the broader MT based corporate actions processing model that many organisations still rely on today.

This article looks at ISO 20022 corporate actions from an operational perspective. Not as a standards discussion, but as a practical shift in how market data is structured, validated and processed, particularly in environments where MT 564 remains part of daily operations.

Corporate actions follow a familiar pattern

In day to day operations, corporate actions follow a well established pattern. Dividend announcements arrive, mergers are announced, stock splits are processed and election deadlines need to be monitored. Each of these events triggers updates across positions, entitlements, reporting and client communication.

For many firms, the market data describing these events still arrives primarily via SWIFT MT messages, most notably MT 564, based on the ISO 15022 standard. These messages are familiar and widely embedded in operational processes, but they rely heavily on interpretation and market practice. Key information is often spread across multiple fields or implied rather than explicitly defined.

ISO 20022 changes how this information is represented. Messages such as seev.031 use structured data models to describe corporate action events and their attributes. The underlying events do not change, but the way they are described does. That distinction matters.

The mixed reality of MT 564 and ISO 20022

In practice, corporate actions market data rarely arrives in a single format. Most organisations receive data from multiple market data vendors and custodians, each following its own migration timeline.

Some sources already deliver ISO 20022 messages, while others continue to rely on MT 564. In many cases, both formats are received at the same time, depending on the market or instrument. Downstream systems, however, still need to present one consistent view of each event.

When MT 564 and ISO 20022 are mixed, workflows break unless the data is normalised early. Without consolidation, organisations are forced to maintain parallel logic, reconcile differences manually and introduce format specific exceptions into otherwise stable processes.

What actually changes in the message

The difference between MT 564 and ISO 20022 becomes most visible when looking at how a single event is represented.

A dividend in MT 564

In an MT 564 message, a dividend is typically described across multiple text based fields. Event type, rate, dates and conditions may appear in different sections, often using abbreviations or encoded values. Important context, such as eligibility or deadlines, frequently depends on interpretation rather than structure.

As a result, downstream systems rely on additional rules, static mappings or manual checks to determine what is actionable and what is informational.

The same dividend in seev.031

In a seev.031 message, the dividend is represented as a structured event. The event type is explicitly defined. Key dates, such as record date, ex date and payment date, are clearly separated. Cash entitlements, currencies and conditions are linked through defined relationships.

This structure allows systems to validate completeness automatically. Missing or inconsistent attributes are immediately visible, reducing reliance on interpretation and experience.

The difference is functional rather than cosmetic. It directly affects how much validation logic and manual handling is required downstream.

Why data quality issues surface during the transition

ISO 20022 often brings data quality issues to the surface that were previously handled implicitly. Corporate actions processing depends on consistent use of identifiers and classifications across currencies, countries, instruments and markets.

This includes standards such as ISO 4217 for currencies, ISO 3166 for countries, ISO 6166 for ISINs and ISO 10383 for market identifiers. When these elements are inconsistent or incomplete, even fully structured messages still require correction before they can be processed reliably.

Converting MT 564 into an ISO 20022 style internal structure helps to standardise downstream handling, but it cannot introduce information that was never present. Native ISO 20022 messages provide richer context, but they only deliver value when combined with consistent validation and normalisation of market data.

How BIQH supports corporate actions during this transition

Many organisations find themselves in a mixed reality today. Corporate actions data arrives in multiple formats, follows different migration timelines and varies in quality across sources. In practice, this often includes vendor specific interpretations of ISO 15022 alongside standard MT messages. Managing that complexity without disrupting existing MT 564 based workflows requires more than format conversion alone.

The BIQH Market Data Platform operates in environments where MT 564 and ISO 20022 coexist. It supports both ISO 15022 and ISO 20022, including full processing of seev.031 corporate action messages. Incoming market data is validated against recognised ISO standards, and non standard or legacy values are automatically transformed into compliant formats.

Regardless of whether corporate actions arrive via MT 564, ISO 20022 messages or market data vendor feeds, the BIQH API delivers a single, consistent market data output that downstream systems can rely on, without forcing immediate changes to existing workflows.

What this means in practice

For corporate actions, ISO 20022 will not replace MT 564 overnight, and there is no single, fixed migration timeline. What it does change is the operational baseline. Corporate actions workflows increasingly need to handle multiple message formats at the same time, while maintaining consistent market data and predictable processing.

Organisations that address this early can reduce manual effort and avoid building format specific logic that becomes difficult to unwind later. Normalising corporate actions data across MT 564 and ISO 20022 creates a stable foundation, regardless of how individual markets or custodians progress in their migration.

Want to explore this in more detail? Download our factsheet or get in touch to discuss how ISO 20022 fits into your current market data setup.