Update to Error Handling Documents
Date of latest update
Type
Change
ID
R0100
Change Category
Change Path
Priority
Urgent
No
Latest Update
02/02/2024 - Draft red-lining under review with impacted Parties. Awaiting feedback prior to Change progression.
Summary
There are duplications between the CSS Message Business Data Validation Rules document (a Category 2 document) and the CSS Error Processing guide (a Category 3 guidance document), which is resulting in confusion and complications within the error handling process. This Change Proposal has been raised to update the Business Data Validation Rules document, to capture the appropriate information that is removed from the CSS Error Processing guide and to ensure alignment with newly created knowledge articles
Impacted Consumers
Status
Implementation Status
Date Raised
Fuel
Date of Update to Priority
Solution Development
Stages Selection
R0100 - Change Proposal Form 16.03.2023
Company Name
-
Review status
Review required
CSS End User Obligations
Date of latest update
Type
Change
ID
R0099
Change Category
Change Path
Priority
Urgent
No
Latest Update
07/02/25 - This Change Proposal has been withdrawn at the request of the proposer, as it is being developed as part of I0180
Summary
There are multiple observed instances of CSS incidents that have been raised that cannot be resolved without proactive engagement from the end user. There are currently no direct obligations on CSS Users to engage with the incident resolution process, or to provide up to date contact details, which can result in the CSS System Operator struggling to resolve incidents in a timely manner. This results in CSS incidents remaining unresolved and results in a degradation of the effectiveness of the switching process. This Change Proposal has been raised to address this issue.
Impacted Consumers
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Date
08 November 2024
| Included changes | Affected REC Items | |
|---|---|---|
| R0105 | Review of ONAGE SLAs |
|
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed Solution Document
Document title
R0099 Draft Legal Text v1.0 (20.03.2024)
Archive
Off
Stages Selection
SME
SME Role
Lead Technical Analyst
SME Role
Lead Assurance Analyst
R0099 - Change Proposal Form 10.03.2023
Company Name
-
Review status
Review required
Optional fuzzy searching in EES
Date of latest update
Type
Change
ID
R0098
Change Category
Change Path
Priority
Urgent
No
Latest Update
08/11/2024 - This Change Proposal has been implemented as part of the November 2024 REC Release.
Summary
This change seeks to introduce new configuration settings in to the EES API - to enable a search to be exact or fuzzy.
Change Plan
Service Provider Impact Assessment window start
Completed
Start:
07 Mar 2023Due:
09 Oct 2023Completion:
09 Oct 2023Service Provider Impact Assessment window close
Completed
Start:
09 Oct 2023Due:
27 Dec 2023Completion:
24 Nov 2024Party Impact Assessment start
Completed
Start:
27 Dec 2023Due:
12 Jan 2024Completion:
12 Jan 2024Party Impact Assessment close
Completed
Start:
12 Jan 2024Due:
02 Feb 2024Completion:
02 Feb 2024Preliminary Change Report and Consultation issued
Completed
Start:
02 Feb 2024Due:
16 Feb 2024Completion:
16 Feb 2024Consultation close
Completed
Start:
16 Feb 2024Due:
08 Mar 2024Completion:
08 Mar 2024Final Change Report issued
Completed
Start:
08 Mar 2024Due:
15 Mar 2024Completion:
15 Mar 2024Responsible Committee decision
Completed
Start:
15 Mar 2024Due:
27 Mar 2024Completion:
27 Mar 2024Appeal window closure
Completed
Start:
27 Mar 2024Due:
12 Apr 2024Completion:
12 Apr 2024Impacted Consumers
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Date
08 November 2024
| Included changes | Affected REC Items | |
|---|---|---|
| R0105 | Review of ONAGE SLAs |
|
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- As a Consumer, I want to be able to switch my electricity easily and efficiently.
- As an organisation providing switching services, I want Consumers to be able to search addresses efficiently.
Proposed Solution Document
Document title
EES Technical Requirement Specification v0.2
Archive
Off
Document title
EES API Interface Specification v3.1.6 - Redline
Archive
Off
Problem Statement
Where a Consumer initiates a Switch through a Supplier, PCW or TPI that utilises the EES API address searches can fail as the API only undertakes “fuzzy” matching. Address Search errors will then need to go through an exception handling process creating an inefficiency and producing a loss of confidence in the Switching process.
Stages Selection
SME
SME Role
Lead Technical Analyst
R0098 - Change Proposal Form 08.03.2023
R0098 - Change Proposal Plan (Approved) 17.10.2023
R0098 - Initial Assessment Report (Approved) 17.10.2023
R0098 Consolidated Party IA Responses v1.0_Non Confidential (16.02.2024)
R0098 - Preliminary Change Report v1.0 published for consultation (16.02.2024)
R0098 - Consolidated Consultation Responses_Non Confidential (15.03.2024)
R0098 - Final Change Report v2.0 Post-Vote (27.03.2024)
Company Name
GB Group plc
Review status
Review required
CSS Message Regeneration Functionality
Date of latest update
Type
Change
ID
R0096
Change Category
Change Path
Priority
Urgent
No
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.
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.
Change Plan
Update to Plan approved at Change Panel
Completed
Start:
Due:
Completion:
21 Oct 2025Impacted Consumers
Impacted REC Services
Status
Implementation Date
05 November 2027
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed Solution Document
Document title
R0096 Solution Development Document V1.0
Archive
Off
Document title
R0096 Detailed Design Document v1.0
Archive
Off
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.
Stages Selection
SME
SME Role
Lead Technical Analyst
SME User
maxime.van-eyseren@capgemini.com
R0096 - Change Proposal Form downloadable version 17.02.2023
R0096 Change Report (Plan) (Approved) V1.0 21.01.25
R0096 Change Report Re-Plan (Pre-Approval) v1.0
R0096 Change Report (Re-Plan) v1.0 approved 21/10/2025
R0096 Change Report (Impact Assessment) v1.0
R0096 Consolidated Party Impact Assessment Responses v1.0
R0096 Change Report (Consultation) approved 17.12.2025 v1.2
R0096 Consolidated Consultation Responses v2.0
R0096 White Paper - Business Case Assessment v1.5
R0096 Change Report (Final Recommendation) approved 25.02.2026 v1.0
Company Name
REC Technical Services
Review status
Review required
Make Shipper NExA values available on the GES portal
Date of latest update
Type
Change
ID
R0088
Other Industry Codes impacted
Change Path
Priority
Urgent
No
Latest Update
03/11/23 - This change was implemented on 03 November 2023 as part of the November 2023 REC Release
Summary
This Change Proposal seeks to deliver the consequential REC changes for Uniform Network Code (UNC) Modification 0701 Aligning Capacity Booking under the UNC and arrangements set out in relevant NExAs. Modification (MOD) 0701 will ensure that the daily capacity allowed by the Network Exit Agreement (NExA) and that permitted by the UNC are aligned.
Change Plan
Initial Assessment and Change Proposal Plan issued
Completed
Start:
16 Jan 2023Due:
24 Mar 2023Completion:
24 Mar 2023Initial Assessment Report and Change Plan approved
Completed
Start:
24 Mar 2023Due:
04 Apr 2023Completion:
04 Apr 2023Service Provider Impact Assessment
Completed
Start:
04 Apr 2023Due:
25 Apr 2023Completion:
24 Apr 2023Party Impact Assessment
Completed
Start:
25 Apr 2023Due:
31 May 2023Completion:
31 May 2023Preliminary Change Report published
Completed
Start:
31 May 2023Due:
16 Jun 2023Completion:
16 Jun 2023Consultation
Completed
Start:
16 Jun 2023Due:
21 Jul 2023Completion:
21 Jul 2023Final Change Report published
Completed
Start:
21 Jul 2023Due:
18 Aug 2023Completion:
18 Aug 2023Responsible Committee decision
Completed
Start:
18 Aug 2023Due:
30 Aug 2023Completion:
30 Aug 2023Impacted Consumers
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Date
03 November 2023
| Included changes | Affected REC Items | |
|---|---|---|
| R0104 | Clarifying requirement for continuous billing following an Erroneous Switch |
Documents
| Name | Version | Last updated | Actions |
|---|---|---|---|
| 1.0 | 08 Jun 2026 |
|
|
| 1.0 | 08 Jun 2026 |
|
Download
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Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- As a Consumer, where I have entered a bi-lateral NExA with the relevant Transporter, I want my Shipper and Transporter to have access to all the data they need when capacity referrals to the Gas Transporters are required.
- As a Gas Transporter, I want the details of the NExA to be held in GES, to increase visibility of the existence of the NExA and to provide details of the offtake parameters.
- As a Gas Shipper, I need to understand both that a NExA exists, and that I have visibility of the offtake parameters relative to the site, so that I can ensure that I take the necessary actions to ensure the Consumer has the appropriate booked Supply Point Capacity.
Proposed Solution Document
Document title
R0088 Gas DAM v3.1 at FCR (18.08.2023)
Archive
Off
Problem Statement
XRN 5186 will make updates to the GES to implement the solution for UNC MOD 701. Following Ofgem’s decision to approve MOD 701, a REC Change Proposal is required to make changes to the REC DAM to enable the delivery of the full cross code solution.
Stages Selection
SME
SME Role
Lead Technical Analyst
R0088 - Initial Assessment Report v1.0 (Approved) 04.04.2023
R0088 - Preliminary Change Report (Post-Vote) 28.06.2023
R0088 - Change Proposal Plan v1.0 (Approved) 04.04.2023
R0088 - Final Change Report v2.0 (Approved) 30.08.2023
R0088 - Final Change Report v1.0 (Pre-Vote) 18.08.2023
Company Name
Xoserve
Review status
Review required
MAP GES data access
Date of latest update
Type
Change
ID
R0087
Change Category
Change Path
Priority
Urgent
No
Latest Update
20/01/25 - Change Proposal withdrawn at proposers request.
Summary
As a MAP I want to be able to track my daily position of my portfolio. As a MAP I want to be able to track changes in my portfolio over time. As a MAP I want to understand who are using my assets and identify where assets are not being used
Impacted Consumers
Impacted REC Documents
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Status
Date Raised
Fuel
Date of Update to Priority
Solution Development
Stages Selection
Company Name
Correla
Review status
Review required
CSS Market Message Retry Strategy
Date of latest update
Type
Change
ID
R0081
Priority
Urgent
No
Latest Update
15/11/2023 - Change Proposal has been withdrawn. Market message success data for September 2023 was reviewed to ensure that a stable period was analysed which represented ‘normal’ conditions. Upon completion of the review, it has been concluded that the success of the current retry strategy has significantly improved since this change proposal was raised. The Code Manager will introduce cyclical reviews of performance to ensure this continues at the expected levels.
Summary
The prescriptive nature of the Market Message retry drafting is currently impeding on the CSS Service Provider’s ability to ensure all Market Messages are sent and received successfully between the CSS and the CSS User. This CP proposes a move to a principles-based obligation that allows for flexibility to ensure the CSS and CSS User are able to attempt retries but not have to follow specific timings or have a maximum number of retries.
Impacted Consumers
Impacted REC Documents
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Status
Date Raised
Fuel
Date of Update to Priority
Solution Development
Stages Selection
R0081 - Change Proposal Form
Proposed legal text submitted with the CP
Company Name
-
Review status
Review required
Improvements to ‘Failed to Deliver’ CSS Messages
Date of latest update
Type
Change
ID
R0080
Change Category
Change Path
Priority
Urgent
No
Latest Update
This Change Proposal has been implemented as part of the REC Release on 27 June 2025.
Summary
Since CSS Go-Live a large number of messages have not been successfully delivered due to failures of CSS User's gateways, resulting in CSS exhausting the 12-hour retry period. This Change Proposal has been raised to explore and address this issue
Change Plan
Service Provider Impact Assessment close
Completed
Start:
09 Nov 2022Due:
25 Jan 2024Completion:
25 Jan 2024Party Impact Assessment trigger
Completed
Start:
25 Jan 2024Due:
02 Feb 2024Completion:
02 Feb 2024Party Impact Assessment close
Completed
Start:
02 Feb 2024Due:
23 Feb 2024Completion:
23 Feb 2024Preliminary Change Report and Consultation issued
Completed
Start:
23 Feb 2024Due:
10 May 2024Completion:
10 May 2024Consultation close
Completed
Start:
10 May 2024Due:
03 Jun 2024Completion:
03 Jun 2024Responsible Committee Decision
Completed
Start:
24 Jul 2024Due:
31 Jul 2024Completion:
31 Jul 2024Final Change Report Issued
Completed
Start:
03 Jun 2024Due:
24 Jul 2024Completion:
19 Jul 2024Impacted Consumers
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Date
27 June 2025
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- As a Consumer, I want the Switching process to work successfully, so that I can switch Energy Supplier without delays or issues.
- As the CSS Provider I want the messages I send to CSS Users to be received and processed successfully, so that there is no interruption to the Switching process or the Consumers’ Switching experience.
- As the CSS User I want to receive CSS messages in a timely manner following any outage of my own gateway or systems, so that there is no interruption to the Switching process or the Consumers’ Switching experience.
Proposed Solution Document
Document title
R0080 - Solution Development Report 11.01.2024
Archive
Off
Document title
CSS Interface Design Specification v8.9.0 R0080 - REDLINE
Archive
Off
Document title
CSS Failed To Deliver Detailed Design (R0080) v1.3 (19.06.2024)
Archive
Off
Document title
Business Data Validation Rules v1.5.0 R0080 - REDLINE
Archive
Off
Document title
Schedule 24_Switching Data Management v1.2_R0080 Draft (19.06.2024)
Archive
Off
Problem Statement
Following an unexpected or extended period of gateway outage for a CSS User, there is currently no automated process to resend any CSS messages from the CSS Provider that were triggered during the period of outage. This results in the CSS Provider needing to manually correct any issues, which is time consuming and may affect Consumer Switches due to delays in messages being processed.
Stages Selection
SME
SME Role
Lead Technical Analyst
SME User
caroline.milner@capgemini.com
SME Role
Lead Assurance Analyst
R0080 - Change Proposal form
R0080 Onboarding document
R0080 - Change Proposal Plan (Approved) 16.01.2024
R0080 - Rebaselined Change Plan (26.04.2024)
R0080 - Initial Assessment Report (Approved) 16.01.2024
R0080 Consolidated Party IA Responses v1.0 (10.05.2024)
R0080 - Preliminary Change Report v1.0 (Published for Consultation) 10.05.2024
R0080 Consolidated Consultation Responses (19.06.2024)
R0080 - Final Change Report v2.0 (Approved) 31.07.2024
Company Name
-
Review status
Review required
Release of Community View Data Items to MEMs in GES
Date of latest update
Type
Change
ID
R0074
Change Category
Change Path
Priority
Urgent
No
Latest Update
05/06/2023 The system changes associated with this change were successfully implemented as planned on Friday 02 June 2023.
Summary
This Change Proposal will enable MEMs to ‘Community View’ access to a limited set of data in the GES, for sites where they are not the appointed MEM.
Change Plan
Service Provider Impact Assessment
Completed
Start:
05 Oct 2022Due:
21 Nov 2022Completion:
16 Dec 2022Party Impact Assessment
Completed
Start:
21 Nov 2022Due:
21 Nov 2022Completion:
18 Dec 2022Preliminary Change Report Issued
Completed
Start:
21 Nov 2022Due:
13 Jan 2023Completion:
13 Jan 2023Consultation closure
Completed
Start:
13 Jan 2023Due:
27 Jan 2023Completion:
27 Jan 2023Responsible Committee Decision
Completed
Start:
27 Jan 2023Due:
22 Feb 2023Completion:
22 Feb 2023Impacted Consumers
Impacted REC Services
Status
Implementation Date
24 February 2023
| Included changes | Affected REC Items | |
|---|---|---|
| R0130 | Updates to the Data Access Matrix |
|
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- As a Consumer, I want a Metering Equipment Manager to be able to access and validate my site details, ahead of their arrival on site for planned or emergency metering work, so that I do not experience any delays in work being completed and can have continuity of supply.
- As a MEM, I want access to sufficient data for sites where I am not the Appointed MEM, to enable me to complete pre-metering works validations of the site details, so I can undertake these works correctly and safely.
- As a MEM, I want access to data for sites where I am not the Appointed MEM, so I can confirm de-appointments and answer invoice validation queries.
Proposed Solution Document
Document title
GES Data Access Matrix for R0074
Archive
Off
Problem Statement
At go-live for REC v3.0 the ‘Community View’ access to data in the GES, previously available via the DES under the UNC, was inadvertently removed. MEMs used this data in a number of processes, including validation of site details prior to metering works – particularly for emergency work, and the resolution of invoice queries from Suppliers. Without access to this Enquiry Service Data, MEMs are unable to complete activities that are central to their operations, including checking site details prior to attending emergency metering works. This has the potential to have a direct negative impact on the experience of metering works for Consumers, and in in some cases, continuity of supply and safety could be at risk.
Stages Selection
Change Proposal Form
R0074 - Change Proposal Plan v1.0
R0074 - Initial Assessment Report v1.0 (Approved)
R0074 - Consultation Responses_NON CONFIDENTIAL
R0074 - Preliminary Change Report v1.0 (Published for Consultation)
R0074 - Final Change Report v2.0 (Post-Vote) 22.02.2023
Company Name
Xoserve
Review status
Review required
Provision of Enduring Test Environments
Date of latest update
Type
Change
ID
R0070
Change Category
Change Path
Priority
Urgent
No
Latest Update
28/06/2024 - Change implemented as part of the June 2024 REC Release
Summary
Currently the REC does not require the Central Switching Service (CSS) and Switching Operator (SO) to provide the enduring test environments and test data for use by REC Parties when making necessary system changes for REC Change Proposals or internal system updates. This Change Proposal has been raised to introduce these obligations in to the REC.
Change Plan
Solution Analysis and Development
Completed
Start:
09 Sep 2022Due:
06 Jun 2023Completion:
06 Jun 2023Service Provider Impact Assessment Period
Completed
Start:
06 Jun 2023Due:
06 Oct 2023Completion:
06 Oct 2023Service Provider Impact Assessment
Completed
Start:
24 Nov 2023Due:
03 Jan 2024Completion:
03 Jan 2024Party Impact Assessment Issued
Completed
Start:
06 Oct 2023Due:
24 Nov 2023Completion:
24 Nov 2023Preliminary Change Report Issued
Completed
Start:
03 Jan 2024Due:
16 Jan 2024Completion:
16 Jan 2024Responsible Committee Review
Completed
Start:
16 Jan 2024Due:
23 Jan 2024Completion:
23 Jan 2024Consultation Issued
Completed
Start:
23 Jan 2024Due:
26 Jan 2024Completion:
26 Jan 2024Final Change Report Issued
Completed
Start:
26 Jan 2024Due:
23 Feb 2024Completion:
23 Feb 2024Responsible Committee Decision
Completed
Start:
23 Feb 2024Due:
05 Mar 2024Completion:
05 Mar 2024Impacted Consumers
Impacted REC Documents
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Date
28 June 2024
Implementation Status
Date Raised
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- As a CSS User I want access to a CSS Test Environment, to enable me to test my systems and processes ahead of the implementation of complex or significant changes, so that I can identify any issues prior to go-live.
- As the SO, I want clarity on the obligations placed on me regarding the provision and maintenance of CSS Test Environments and data, so that I can meet my obligations and provide CSS Users and Service Providers with access to appropriate Test Environments.
- As a Switching Data Service Provider (SDSP), I want clarity on the obligations placed on me regarding the provision and maintenance of Test Environments and data, so that I can meet my obligations to test CSS changes. As a Switching Data Service Provider (SDSP), I want access to a CSS Test Environment, to enable me to test my systems and processes ahead of the implementation of complex or significant changes, so that I can identify any issues and address prior to go-live.
Proposed Solution Document
Document title
R0070 legal text v1.0 - Published with Impact Assessment
Archive
Off
Document title
R0070 Legal Text v2.0 - Published with Preliminary Change Report
Archive
Off
Document title
R0070 - Legal Text v3.0 - Approved for Implementation
Archive
Off
Document title
REC Category 3 - Environment Management Plan
Archive
Off
Document title
REC Category 3 Test Data Management Plan
Archive
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Problem Statement
For specific types of changes, industry system testing will be required to ensure the end-to-end Switching processes will work as expected following implementation. If Test Environments and Test Data are not available, CSS Users will not be able to complete testing to confirm their systems will operate correctly in the live environment. The REC currently doesn’t define specific obligations on Service Providers regarding enduring test systems and Test Data for Switching processes. The lack of specific obligations may impact the availability of appropriate Test Environments. This could impact the progression of improvements to Switching processes that require a technical change.
Stages Selection
SME
SME Role
Lead Technical Analyst
SME User
beth.brown@capgemini.com
R0070 Initial Assessment Report v1.0 (Approved)
R0070 - Preliminary Change Report (Approved 23.01.2024)
R0070 - Change Proposal Plan v2.0 (Approved)
R0070 - Change Proposal Form
R0070 - Consolidated Impact Assessment Responses
R0070 - Consolidated Consultation Responses
R0070 - Final Change Report V2.0 (Post-Vote) 05.03.2024
Company Name
-
Review status
Review required