Faster, further and stronger with ISO 20022: the keys to a successful migration


After many years of patient development, the ISO 20022 payments standard is gaining ground and revolutionising the world of payments and reporting, particularly for correspondent banking and cash management activities. ISO 20022 is a global standard designed for the exchange of computerised data in financial transactions. It aims to streamline the communication between players in the global payments ecosystem by offering them a standardised means of communication.

Finally being able to speak the same language is a genuine revolution in the world of payments!

In a world becoming increasingly fragmented in technical and geopolitical terms, ISO 20022 provides market players with common tools and instructions for use. It supports financial inclusion and trade growth by making payment processes from one user to another more efficient, improving interoperability between different settlement systems and providing a springboard for innovation through the richer and better structured information it conveys.

However, like any evolution, the adoption of ISO 20022 requires effort. It poses challenges to all players in the payment chain in terms of technology, investments in financial and human resources, training and discipline. The aim is to gradually impose uniform use across different payment ecosystems and multiple jurisdictions. This is why the cross-border payments industry has given itself three years to migrate to ISO 20022, with the help of the interbank cooperative Swift, which has 11,000 members worldwide. March 2023 marked the start of this gradual migration for correspondent banking payment messages, as well as for high-value payment systems in the eurozone, Australia, New Zealand and Canada. The UK followed in June. And other major high-value systems are set to migrate in the coming months (e.g. CHIPS for the US dollar and CHATS for the Hong Kong dollar in April 2024, Fedwire for the US dollar in March 2025). In short, the migration of the payment ecosystem will continue to gain momentum worldwide, right up to the November 2025 deadline set by the banking industry.

After reading the interesting white paper from BAFT (Bankers Association for Finance and Trade) entitled ISO 20022 Migration: Lessons Learned ( published on 10 January 2024, our experts are contributing to the debate by looking back at the experiences gained by our Group during the migration of our cross-border payments business to ISO 20022. It is a testimonial and a collection of best practices that may prove useful to financial players who have yet to make the big leap into the promising realm of ISO 20022!

The choice of an “ISO native” target solution

From the outset, the Societe Generale Group chose to focus its efforts on a complete ISO 20022 target solution. Faced with such a vast project for banking groups with many branches, it can be very tempting to install conversion tools that preserve legacy applications. But this "patchwork" approach will prove counter-productive over time, because it will prevent your in-house applications from taking advantage of the richer and better structured data of the ISO 20022 format to innovate, automate processing, and in short, improve performance.

Societe Generale chose to migrate all payment processes of its entities worldwide to ISO 20022 by November 2025. Roadmaps are planned for each application. Each will move towards ISO 20022 at its own pace.

Being a “native ISO” requires significant change management measures. It is important to ensure that back and middle office staff have the right tools at their disposal, based on the so-called "data lakes", properly configured for ISO. They must be trained to read, interpret and process the new message format and the new information conveyed. Not to mention the need for a major overhaul of all procedures.

The training of in-house resources needs to be planned over time, anticipating the activities to be carried out well in advance. Starting training one year before migrating is not a luxury! Employees will need to take part in several sessions before the go live. We’re not all moving at the same pace, so bear in mind that your counterparties will probably also be on different learning curves. Change management will be gradual.

A choice of governance combining centralisation and local freedom of action

To achieve what the industry describes as a tour de force, Societe Generale also opted for a “combined” project management. First of all, we set up a centralised group programme department within our Global Transaction and Payment Services (GTPS) division. It was our compass in the months leading up to our migration in March 2023; it monitored interbank developments as closely as possible and kept the various stakeholders informed while enabling them to make coordinated choices.

Then, each of our entities was given the opportunity to organise itself according to its needs, by being responsible for its own budgets, impact analyses, development schedules and change management. This combined approach proved to be a winner! Centralised information has enabled us to share and cascade expertise within our group in a smooth and methodical manner. The considerable freedom of action given to each entity, although very demanding for each business line in terms of resources to be allocated, has enabled our units to remain more agile, closer to their field of activity and to their clients.

The importance of regularly sharing information with all stakeholders

In order to provide input to our Group’s ISO 20022 project management team, our interbank specialists quickly became involved in the work and discussion groups of the various French and European market bodies, the Swift cooperative, our market infrastructures, central banks and standardisation organisations.

We are proud to have played an active role in the working groups that have sought to harmonise standards and rules of use for payment systems (HVPS+ group1) and Correspondent Banking (CBPR+2).

“It is indeed important to be able to communicate regularly and transparently with industry peers to anticipate potential difficulties so that we can better resolve them together, and to exchange best practices.” Sylvain Dauge, Product Manager, Cash Clearing Services

You feel less alone when the burden is shared! We can help each other and work on resolving any interoperability issues. Change management communications with our clients were provided systematically from the year preceding our migration. We used a variety of channels: webinars, short impact videos lasting just a few minutes sent to our bank clients, bilateral meetings with ISO experts accompanying our relationship managers and presentations at industry conferences (BAFT, SIBOS, etc.). The legal aspect was dealt with, but the actions to be taken at contractual level proved limited because, although the format of the exchanges has changed, the services offered have not been affected in any way.

Particular attention was paid to the tests: specific emails and communications were sent to our banking clients to offer them guidance. It is also interesting to note that this support activity continues today, one year after the start of the migration, both with our banking clients who have adopted a different ISO adoption schedule, and also with the entities of our group whose local market infrastructures still need to migrate.

Test, test and test again!

The testing part is essential. We can't stress this enough! It is vital to perform end-to-end testing before migrating. From bank to bank, of course, but also from client to client. Tools such as My Standards and the Readiness Portal, offered by the interbank cooperative Swift, can provide valuable help in checking that flows are already compliant before carrying out full tests. Make sure you start your tests as early as possible and make them systematic, both with market infrastructures and your correspondent banks.

“You can't stop testing at messages reception, you have to test the whole process, right up to the accounting and the credit to the end client's account.” Laurence Doré, ISO 20022 Program Director

This will give you the certainty that everything will work on the big day. The pitfalls are not necessarily where you expect them! Test environments must be carefully organised; there are many use cases and it takes time to prepare them. Messages testing should be as close as possible to the content of your production flows, to reflect the reality of the live traffic flow. And don’t forget to break down silos! You need to be open to external counterparties who are willing to work with your teams. One of you may spot a problem that no-one has seen before. United we stand!

“Cooperation is essential if you are to seamlessly migrate your payments to ISO 20022 because it enables you to standardise your understanding of formats and of formatting, i.e. the way each one “fills in” messages.” Virginia de Vito, Project Director

Finally, performance tests will have to be carried out meticulously. Did it all work out? Great! So it’s time to see how systems and other applications react when faced with the stress of large volumes. Don’t hesitate to take part in the rehearsal windows that will be offered to you by your market infrastructures. It's a lot of work, but your teams won't regret it.

Bear in mind, however, that the tests, as comprehensive as they are, will probably not completely protect you from surprises in the first few days of your migration. Be ready to react immediately, with your IT teams on standby, ready to put on the life jacket to correct any anomalies detected. As the world of payments is particularly “creative”, there is bound to be a complex banking case that had not been anticipated. 

In fact, as you probably knew, our ISO 20022 adventures won’t stop when the migration is over! Find out more about the challenges and opportunities facing our industry in the months and years ahead in the article “Faster, further and stronger with ISO 20022: the outlook for 2024 and beyond”.

1Swift, together with the world’s leading banks and market infrastructures, formed the HVPS+ Market Practice Task Force. While ISO 20022 standards are constantly evolving, good stability practices for high-value payments have been published, and the industry now has a roadmap for harmonisation. High Value Payments Plus (HVPS+) – the next stage step towards ISO 20022 Harmonisation | Swift

2Cross-border payments and reporting plus (CBPR+) is a work group of payments experts whose mission is to create global guidelines on business practices and the implementation of ISO 20022 to ensure harmonised deployment and implementation by banks.