CSS Message Regeneration Functionality
Summary
An inability by the Central Switching Service (CSS) to re-generate Market Messages that were not sent as intended can result in issues with the Switching process, both for REC Parties, and Consumers. This Change seeks to create a message regeneration functionality that would mitigate this Consumer detriment.
Latest update and next planned activity
Date of latest update
Latest Update
25/02/2026 On 25 February 2026, the Technical Expert Panel voted in line with the Code Manager recommendation to approve R0096 for implementation in November 2027. The appeal window is now open until 23:59, 11 March 2026.
Impacts Overview
Impacted Consumers
Electricity
Gas
Domestic
Non-Domestic
Impacted REC Services
Central Switching Service (CSS)
Priority and rationale
Standard
Priority last updated on 29 May 2026
Solution development
Problem Statement
Failures by the CSS to generate Market Messages can result in a breakdown of the Switching process. As the CSS cannot re-generate Market Messages that should have been sent but were not, this results in message asynchronisation, and breakdown of CSS functions and processes, resulting in substantial impacts for those involved – Difficulties for the REC Parties using the CSS, and difficulties for Consumers, where the Switch process is impacted.
No documents available.
Change Plan
Update to Plan approved at Change Panel
Completed
Start:
Due:
Completion:
21 Oct 2025Original submission
Change details
Michael Taylor - REC Technical Services
17 Feb 2023
Change details
CSS Message Regeneration Functionality
Since CSS Go-Live there have been incidents whereby messages have been unsuccessfully generated by CSS and therefore are not delivered to the intended recipient.
When CSS does not generate a message it results in a failure of the Switching process and can cause significant complications for the intended recipient, who is required to manually intervene to re-synchronise messages. This is a highly visible issue that is causing significant strain to industry.
CSS is able to identify and regenerate messages that failed initial generation, such that the message recipient is not impacted.
Rectification of CSS message generation failures causes significant operational strain to message recipients when undertaking incident resolution.
Impacts
Electricity, Gas, Domestic Prepayment, Domestic Credit, Microbusiness, Small and Medium Enterprise (SME), Industrial and Commercial (I&C)
Switching experience
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No details provided
Not currently known - potential for no REC schedule to be impacted.
No details provided
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No details provided
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No details provided
Not currently known - potential the Data Specification to be impacted.
No details provided
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Central Switching Service (CSS)
Intention is to progress the addition of centralised functionality to CSS, such that CSS Users are not impacted.
No details provided
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No details provided
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No details provided
Priority & timing
No
Should switching volumes increase, it could have serious implications on switching experience due to slow resolution of incidents and failed switches.
As soon as practicable.
Delivery of other CSS changes will need to be considered.
No details provided
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Activity
Status has been changed to Awaiting Implementation.
Implementation Date has been updated to 05 Nov 2027.
Status has been changed to Solution Development.
maxime.van-eyseren has been allocated as SME.