ISO 20022 Handbook

1. Introduction

This ISO 20022 handbook contains all necessary information on the Bank’s migration of CHAPS to ISO 20022 messaging. It provides comprehensive information on our approach, policies and timelines, as well as signposting key technical resources, such as the location of technical documents and detail about industry readiness and testing. This document replaces previous publications such as the CHAPS and RTGS ISO 20022 migration publication that was issued in October 2020 and updated in September 2021.

This information is aimed at CHAPS Direct Participants, CHAPS indirect participants and technology partners. It also includes information relevant for payment users who make, receive or process CHAPS payments, or other stakeholders with an interest in the future of UK payments. CHAPS Direct Participants in particular should ensure full understanding of information in this ISO 20022 handbook, while Section 4 - non-payment message migration, is also relevant for RTGS Reserves and Settlement Account Holders.

2. CHAPS migration timetable and approach

The below timetable contains key milestones that will impact CHAPS participants and RTGS account holders.

20 June 2022 – Pilot Platform

• Since summer 2022, we have been providing a Pilot platform for CHAPS Direct Participants, to support extended testing of enhanced ISO 20022 messages prior to live implementation.
• From 20 March 2023, the Bank’s Euro Liquidity Bridge service will be operated manually for an interim period, up until the new settlement engine goes live on summer 2024. From 20 March 2023, DPs will be required to first contact the Bank (using their institution’s standard communication with the Bank for RTGS, either by calling the PSC helpdesk or by emailing psc.secure@bankofengland.co.uk) before they fund the Bank’s euro cash collateral account at DNB. More information on the Euro Liquidity Bridge can be found in Section 7 and the full process detailed in the publication: Euro Liquidity Bridge – changes for CHAPS Direct Participants ahead of ISO 20022.

19 June 2023 – Enhanced ISO 20022 messaging in CHAPS

We migrated the live CHAPS service to ISO 20022 messaging on 19 June 2023. At this point:

• CHAPS moved to the SWIFT InterACT service. All CHAPS Direct Participants will need to be able to receive enhanced ISO 20022 payment messages using only the enhanced XML message schemas. The data sent in CHAPS payments must now contain at minimum the requirements and rules for the existing MT message formats, and sending enhanced data will be optional. However, we encourage Direct Participants to send enhanced data (i.e. above that required or supported in existing MT message formats) where possible, taking into account relevant international guidance. For more detail, please see our Policy Statement: Implementing ISO 20022 Enhanced data in CHAPS.
• CHAPS Direct Participants are able to choose whether to send/receive non-payment messages (e.g. statements, notifications and liquidity-related messages) in either the existing MT or the new ISO 20022 format between now (post-Transition State 2.1) and Transition State 3.
• See the relevant sections in this document for further details on Truncation Risk and non-payment message migration.

2024 - new RTGS core settlement engine

The new RTGS core settlement engine will go live in 2024, at which time:

• The requirements for CHAPS payment messages remain the same as from 19 June 2023. In other words, CHAPS Direct Participants must continue to be able to receive enhanced messages, and are encouraged to send enhanced data in their messages where possible, but this will be optional.
• All CHAPS Direct Participants will need to send and receive non-payment messages (for example, statements, notifications and liquidity-related messages) in the relevant ISO 20022 format.
• From 2024, we will mandate certain elements of enhanced data. Given the updated timelines for the implementation of ISO 20022 in CHAPS, we will start mandating the use of these data fields from November 2024, maintaining the window between implementation and mandating. In particular, it will mandate the use of Purpose Codes and LEIs for payments between financial institutions (all pacs.009 CORE messages and certain pacs.008 messages). It will also mandate Purpose Codes for property transactions. For more detail, please see our Policy Statement: Implementing ISO 20022 Enhanced data in CHAPS. For more detail on the scope, please see our Additional Guidance: Detail on Mandating ISO 20022 Enhanced Data in CHAPS. 

Beyond 2024

• From November 2025, we will mandate the use of Structured Addresses and Structured Remittance Data for all CHAPS payments in line with the developments in the implementation for cross-border payments. We will consider further enhancements to ISO 20022 message schemas and the CHAPS rulebook to mandate or incentivise full use of the ISO 20022 messages (please see our Policy Statement: Implementing ISO 20022 Enhanced data in CHAPS). 
• From November 2025, we intend to implement a programme of regular upgrades to the CHAPS enhanced messaging schemas. We will support this approach by introducing a new Change Management Framework for CHAPS ISO 20022 messages. This will provide a transparent and inclusive approach to updating ISO 20022 CHAPS messages. The approach will allow us to update in line with the latest versions of ISO 20022, in coordination with other domestic and global market infrastructures. It will also facilitate the implementation of policy changes such as purpose code revisions and allow CHAPS Direct Participants to propose and agree changes.
• In spring 2022, the Bank consulted with industry on a set of ambitious and innovative features that could be implemented in the renewed RTGS system, once the new core settlement engine goes live in 2024. While work continues to develop these features, participants may see further guidance published by the Bank in future, potentially including new uses for existing or new ISO 20022 message types. More information, including the outcomes of the consultation can be found in the publication; Roadmap for Real-Time Gross Settlement service beyond 2024.

3. ISO 20022 message schemas and how to access them

MyStandards

We have published on MyStandards  the enhanced ISO 20022 message schemas for the CHAPS and Reserves and Settlement Account Holders, together with further Technical Guidance. 

The current enhanced message schemas are up-to-date and align with the latest international market practice. These are the message schemas that CHAPS Direct Participants and Settlement and Reserves Account Holders should implement and develop against, in line with the ISO 20022 approach and timelines as set out in this section and Section 1. 

Publication on Standards Source

We will publish the message schemas on Standards Source to provide a direct comparison with Pay.UK’s New Payments Architecture (NPA) message schemas when these are available. Standards Source is an alternative tool, which is used by the UK’s Pay.UK. MyStandards is the Bank’s authoritative ‘golden copy’ of the message schemas, and participants should always refer to the MyStandards version to implement, develop and test their CHAPS message schemas.

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Return messages

On 19 June 2023, we introduced the pacs.004 return message, which does not have an MT equivalent. This replaces the existing practice of returning payments via MT 202 messages. Further detail is provided in the Technical Guidance found on MyStandards.

Migration of collateral-related messages 

Interim procedures on operation of the Euro Liquidity Bridge facility can be found in the publication: Euro Liquidity Bridge – changes for CHAPS Direct Participants ahead of ISO 20022. This will be operated manually from 20 March 2023 when TARGET2 migrates to ISO 20022, until Transition State 3. DPs will need to contact PSC prior to funding the Bank’s Euro cash collateral account at DNB using their institution’s standard communication with the Bank for RTGS (either by calling the PSC helpdesk or via email psc.secure@bankofengland.co.uk). 

Any securities messages to manage other collateral movements (via the Bank’s collateral management systems, which are separate to RTGS) will remain in the FIN MT format for the foreseeable future. The Bank’s long-term intention is that these will move to ISO 20022 messages, however we are prioritising the migration of payment messages prior to November 2025. 

List of messages used in CHAPS

4. Non-payment message migration

Non-payment messages will also be migrating to the new ISO 20022 format. These include the existing statement, notification and report messages, MT 298/nnn and MT 950 messages, which are only received by Direct Participants.

If your organisation currently receives a daily statement directly from RTGS, you will need to update your internal systems to be able to accept the new camt.053 message before summer 2024. 

Previously the Bank gave Direct Participants the option to migrate to receiving daily statements as a camt.053 ISO 20022 message at either ISO 20022 go-live (previously April 2023 and named Transition State 2.1) or go-live of the new RTGS core settlement engine (previously summer 2024 and named Transition State 3). The Bank will adapt these choices to the updated timetable as below:

• Direct Participants that opted to migrate to these messages to ISO 20022 when CHAPS transitions from MT to ISO saw these messages migrate on 19 June 2023.
  
• Those Direct Participants who opted to receive daily statements as camt.053 from the new RTGS core settlement engine implementation (previously called Transition State 3, in summer 2023), will now migrate in summer 2024 in line with the updated (February 2023) timetable.
  
• Settlement and Reserves Account Holders will also migrate to receive daily statements as camt.053 from summer 2024 when the new RTGS core settlement engine goes live. 
• If you are not ready to receive the camt.053 messages by the relevant date applicable to you, you may be able to build or buy a translator service to convert the camt.053 message into MT 950 messages for use in your internal systems.

If you have any queries or may need to alter when you receive non-payment messages in ISO 20022 format, please contact RTGSReadiness@bankofengland.co.uk. More information can be found in the historic publication: Migration approach of non-payment messages to the ISO 20022 messaging standard. This is a static document so please check dates against this ISO 20022 Handbook.

5. Enhanced data policy and guidance

The Policy Statement: Implementing ISO 20022 Enhanced Data in CHAPS sets out the Bank’s policy position for the implementation of enhanced data in CHAPS through the ISO 20022 messaging standard. It includes a roadmap for how we intend certain policies around enhanced data to evolve in the years following implementation. It also summarises the responses to the policy questions under Section 2 of the July 2020 Industry Review, which followed the November 2018 consultation response document. 

As of 19 June 2023, the Bank supports enhanced data and strongly encourages each Direct Participant to use enhanced data once they are capable of sending (subject to where international guidance discourages its use ahead of November 2023, see Section 5 above). From late 2024, we will mandate the use of Purpose Codes and LEIs for CHAPS payments between financial institutions, and mandate the use of Purpose Codes for property transactions. Given the updated timelines for the implementation of ISO 20022 in CHAPS, we will start mandating the use of these data fields from November 2024, maintaining the window between implementation and mandating. For further information on Purpose Codes please see the UK recommended Purpose Code list and Consultation response on Purpose Codes in ISO 20022 Payment Messaging. When SWIFT retires MT messaging for payments (currently expected in November 2025), we expect to mandate the use of structured addresses and structured remittance data for all CHAPS payments. 

We have continued our close collaboration with Pay.UK on implementing ISO 20022 messaging standards to ensure interoperability between CHAPS and the New Payments Architecture (NPA) where appropriate. In particular, to facilitate the introduction of Purpose Codes, the Bank and Pay.UK have jointly developed a UK recommended list of Purpose Codes for payments made through either CHAPS or the New Payments Architecture.

For more detail on how each type of enhanced data will be mandated, please see our Additional Guidance: Detail on Mandating ISO 20022 Enhanced Data in CHAPS.

Market Guidance

The Bank’s approach to working with industry to develop ISO 20022 Market Guidance was outlined in our Policy Statement: Implementing ISO 20022 Enhanced data in CHAPS.

On 14 April 2021, the Bank published the first Market Guide: Implementing ISO 20022 messaging in CHAPS covering property payments. On 3 February 2022, the Bank then published the second Market Guide for the corporate market sector. These guidance documents have been commissioned independently on behalf of the Bank, based on engagement with industry. The Bank will continue working with industry stakeholders to define market best practice guidance for implementing the ISO 20022 messaging standard in order to realise the benefits of enhanced data.

Note these Market Guidance publications are static documents so please check dates with this ISO 20022 Handbook.

6. Euro Liquidity Bridge – Change for CHAPS direct participants ahead of ISO 20022 migration

As operator of CHAPS, the Bank offers and operates a ‘Euro Liquidity Bridge’ which allows CHAPS Direct Participants (DPs) to use Euro cash sent to the Bank via TARGET2 as collateral to raise intraday Sterling liquidity in RTGS.

As part of the European Central Bank, Eurosystem T2-T2S consolidation project, TARGET2 payments will migrate to ISO 20022 on 20 March 2023. Prior to this, De Nederlandsche Bank (DNB) has also launched a new Payments Hub to replace customer accounts currently held on the Home Accounting Module (HAM) in TARGET2. For an interim period between March 2023 and summer 2024, the current RTGS system will be unable to process ISO 20022 format messages from DNB.

Following a review of the current facilities and discussions with frequent users, we have developed a solution to continue operating the Euro Liquidity Bridge without causing excessive impact or costs to either the Bank or DPs. The required changes and solution for DPs is detailed in the publication: Euro Liquidity Bridge – changes for CHAPS Direct Participants ahead of ISO 20022.

7. Participant and readiness testing

The Bank is providing a range of testing tools to participants as part of our CHAPS ISO 20022 transition, in order to support participant preparations. Please see below for detail about the tools available, and our expectations for CHAPS Direct Participants to use them to support their preparations and indicative timelines for their availability.

MyStandards Readiness Portal

The MyStandards Readiness Portal allows users to validate their CHAPS payment messages against the published enhanced message schemas. All CHAPS Direct Participants are expected to make use of the Readiness Portal and indirect participants and software vendors supplying payment systems can also access the portal via a Direct Participant. The Bank monitors Direct Participants’ use of the Readiness Portal as part of our approach to assuring industry readiness for the migration.

Participant Test Simulator – from early 2022

The Test Simulator provides a solution for RTGS participants to receive inward test payment messages to themselves, removing the reliance on other participants. The Test Simulator is able to ingest and generate messages from bespoke message schemas built on industry standard ISO 20022 messages. In addition, the Bank is using the Test Simulator for its own internal testing. 

Pilot Platform – from 20 June 2022

Since 20 June 2022, the Bank has made available a Pilot Platform test environment, allowing all CHAPS Direct Participants an extended testing period for enhanced ISO 20022 messages in a near live-like environment. 

Participant Testing – October 2022

Direct Participants completed Participant Testing in October 2022 ahead of the planned migration to ISO 20022 messaging in June 2023. The Bank issued a minimum set of test cases for each Direct Participant to complete (Participant Acceptance Testing), alongside their own testing plans using either a test simulator or a ‘buddy’ bank. Once Direct Participants successfully completed this testing, a more structured test phase (‘Group Testing’) allows DPs to test multi-laterally with each other, including contingency and volume test scenarios. An additional test window at the end of Group Testing has been planned for any post regression test fixes that may be applied as a result of ECB go live.

For any queries on Participant Readiness and Testing, participants should contact RTGSReadiness@bankofengland.co.uk. 

8. Future maintenance to ISO 20022 messages

Once SWIFT has retired MT payment messages (currently expected in November 2025), the Bank will introduce its Change Management Framework and annual change cycle, which establishes the ongoing change and maintenance process for the CHAPS ISO 20022 messages. 

Until November 2025

The Bank will only make changes to the message schemas and Technical Guidance where such changes are critical. This is likely to be either: 

• Where an error or ambiguity is evident and making an update to the documentation will provide a clear and significant benefit to users of the messages and/or the Bank; 
• Where international guidance has changed and the Bank needs to align its documentation in order to avoid a tangible risk to participants, the Bank, and/or wider industry. For example, this could be a change to SWIFT’s CBPR+ (Cross-Border Payments and Reporting) that if not aligned would cause truncation challenges for participants. 

After November 2025

From November 2025 we intend to implement a programme of annual upgrades to the CHAPS enhanced messaging schemas. This approach will be supported by introducing a new Change Management Framework for CHAPS ISO 20022 messages. This will provide a transparent and inclusive approach to updating the ISO 20022 CHAPS messages. The approach will allow us to move to the latest versions of ISO 20022 (in coordination with other domestic and global market infrastructures), implement policy (such as structured address), and allow CHAPS Direct Participants to propose and agree changes.

9. Previous documents