Missing Scenario Variants in D0179 Alternate Solution
Date of latest update
Type
Change
ID
R0235A
Change Category
Other Industry Codes impacted
Change Path
Priority
Urgent
No
Latest Update
This Change Proposal has been implemented as part of the February 2026 REC Release.
Summary
Within MHHS SIT there is a scenario where the LDSO generates a D0139 to the MS for a PPM but the requirement is for the MS to generate a D0179. There is a gap in the D0179 data required and that provided on the D0139. 21.5.1 & 21.5.6 under Schedule 14 states that where the DNO changes the energisation status, within 3 WD of changing the energisation status the DNO will send the D0139 or the D0179(21.5.6) to the MS and then the MS will generate the D0179 to the Supplier(21.5.6). Currently, the LDSO only generates the D0179 to the Supplier but not to the MOP and the only change under MHHS is to add the new variant MSS.
Original CP
Impacted REC Documents
Impacted REC Parties and Market Participants
Status
Implementation Date
27 February 2026
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed Solution Document
Document title
R0235A Schedule 14 - Metering Operations current draft
Archive
Off
Document title
R0235A Schedule 14 - Metering Operations MHHS draft
Archive
Off
Problem Statement
DNOs and MOAs cannot fulfil their full obligations listed in Schedule 14 Metering Operations as there missing Scenario Variants in the Data Specification preventing them from sending the D0179 to all required Parties. This alternate solution proposes the removal of the D0179 from the legal text and the D0139 to be used in all scenarios.
Stages Selection
R0235A Change Proposal form
R0235 and R0235A Change Report (Final Recommendation) V2.0 (Approved) 01.07.2025
Company Name
-
Review status
Review required
Update to R0060 Implementation Date
Date of latest update
Type
Change
ID
R0250
Change Category
Other Industry Codes impacted
Change Path
Priority
Urgent
No
Latest Update
28/05/25 - On 28 May 2025 the Technical Expert Panel approved R0250, resulting in the implementation of R0060 being moved from 27 June 2025 to the ‘First available release after MHHS Milestone 8 – Code changes delivered’.
Summary
Without an update to the implementation of R0060 complexity is created for MHHS code drafting implementation as the MHHS design details in its operational choreography document that all timings are in clock time unless stated as otherwise.
Change Plan
Change Proposal approved by Technical Expert Panel
Completed
Start:
12 May 2025Due:
28 May 2025Completion:
28 May 2025Consultation completed
Completed
Start:
25 Mar 2025Due:
12 May 2025Completion:
12 May 2025Impacted 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
Problem Statement
Without an update to the implementation date of R0060, the intent of the original proposed implementation date cannot be achieved. If the implementation date remains as 27 June 2025 complexity will be created for the implementation of MHHS code drafting as the MHHS design details in its operational choreography document that all timings are in clock time unless stated as otherwise.
Stages Selection
SME
SME Role
Lead Technical Analyst
SME User
beth.brown@capgemini.com
SME Role
Lead Assurance Analyst
SME User
vaishnsharma@deloitte.co.uk
Change Proposal form
R0250 Change Report (Proposal Plan) v2.0 (Approved) 15.04.2025
R0250 Change Report (Consultation) V1.0 16.04.2025
R0250 Consolidated Consultation Responses v1.0
R0250 Change Report (Final Recommendation) v2.0 (Post-Vote) 28.05.2025
Company Name
-
Review status
Review required
REC Changes to tie in with DCP451 - Suspending Registrations
Date of latest update
Type
Change
ID
R0248
Change Category
Other Industry Codes impacted
Change Path
Priority
Urgent
No
Latest Update
This Change Proposal was implemented as part of the 7 November 2025 REC Release.
Summary
A DCUSA Change Proposal - DCP 451 ‘Suspending Registrations’ - has been raised to look into this issue. The solution must consider a cross-code solution, which does not put consumer outcomes at risk.
Change Plan
Change Report (Proposal Plan) approved by Change Panel
Completed
Start:
Due:
Completion:
17 Jun 2025Change approved
Completed
Start:
Due:
Completion:
05 Aug 2025Impacted REC Documents
Impacted REC Parties and Market Participants
Status
Implementation Date
07 November 2025
| Included changes | Affected REC Items | |
|---|---|---|
| R0003 | Market-wide Half-Hourly Settlement Implementation |
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed Solution Document
Document title
I0248 Switching Data Management draft
Archive
Off
Problem Statement
A lack of clarity on the process for when a DNO ends a Regulatory Alliance with an Energy Supplier can cause confusion with the Energy industry, and lead to poor Consumer outcomes if the correct process is not followed.
Stages Selection
SME
SME Role
Lead Assurance Analyst
SME User
vaishnsharma@deloitte.co.uk
Issue proposal form
I0248 Change Report (Proposal Plan) V1.0
R0248 Change Report (For Consultation) v1.0
R0248 Consolidated Consultation Responses V1.0
R0248 Change Report (Final Recommendation) V1.0 - approved 05.08.25
Company Name
-
Review status
Review required
Effective Dates in EES
Date of latest update
Type
Issue
ID
I0247
Other Industry Codes impacted
Urgent
No
Latest Update
12/08/2026 - the Proposer has chosen to withdraw this Issue as MHHS means many of the effective dates are being updated as per the original business case so the change is no longer required.
Summary
On a switch many of the effective dates within EES default to the switch date. This includes energisation status. It means EES users that don't have access to the meter technical details do not know the actual date the status changed.
Impacted REC Documents
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Status
Implementation Status
Date Raised
Fuel
Date of Update to Priority
Solution Development
Stages Selection
Stages Selection
Proposal Form
Company Name
-
Review status
Review required
Missing Scenario Variant from R0043
Date of latest update
Type
Change
ID
R0242
Change Category
Change Path
Priority
Urgent
No
Latest Update
This Change Proposal has been implemented as part of the February 2026 REC Release.
Summary
There is a missing scenario variant from the introduction of R0043 – Schedule 14 Metering Operations states the Crowded Meter Room MOA (CMRM) should send a D0139 to the Supplier and DNO but the scenario variant of CMRM to DNO is missing.
Change Plan
Proposal Plan approved at Change Panel
Completed
Start:
Due:
Completion:
18 Mar 2025Final vote at Technical Expert Panel
Completed
Start:
Due:
Completion:
25 Jun 2025Impacted REC Parties and Market Participants
Status
Implementation Date
27 February 2026
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Problem Statement
CMRMs currently cannot send all the Market Messages required of them in Schedule 14 Metering Operations.
Stages Selection
Change Proposal form
R0242 Change Report (Proposal Plan) V1.0 Approved 18.03.25
R0242 Consolidated Impact Assessment Responses
R0242 Change Report (For Consultation) V1.0
R0242 Consolidated Consultation Responses v1.0
R0242 Change Report (Final Recommendation) V1.0 approved 25.06.25
Company Name
-
Review status
Review required
Missing Scenario Variants in D0179
Date of latest update
Type
Change
ID
R0235
Change Category
Change Path
Priority
Urgent
No
Latest Update
01/07/2025 - On 01 July 2025, the REC Change Panel voted to reject R0235 and approve R0235A, in line with the Code Manager's recommendation. The appeal window has closed.
Summary
Within MHHS SIT there is a scenario where the LDSO generates a D0139 to the MS for a PPM but the requirement is for the MS to generate a D0179. There is a gap in the D0179 data required and that provided on the D0139. 21.5.1 & 21.5.6 under Schedule 14 states that where the DNO changes the energisation status, within 3 WD of changing the energisation status the DNO will send the D0139 or the D0179(21.5.6) to the MS and then the MS will generate the D0179 to the Supplier(21.5.6). Currently, the LDSO only generates the D0179 to the Supplier but not to the MOP and the only change under MHHS is to add the new variant MSS.
Change Plan
Change Report (Proposal Plan) approved by Change Panel
Completed
Start:
Due:
Completion:
04 Mar 2025Presented at Change Issues Group
Completed
Start:
Due:
Completion:
06 Mar 2025Presented at Change Issues Group
Completed
Start:
Due:
Completion:
01 May 2025Presented at REC Change Panel
Completed
Start:
Due:
Completion:
20 May 2025Alternative Change Proposals
Impacted REC Documents
Impacted REC Parties and Market Participants
Status
Implementation Date
27 February 2026
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed Solution Document
Document title
I0235 D0179 Missing Scenario Variants
Archive
Off
Document title
R0235 Data Specification V0.2
Archive
Off
Problem Statement
DNOs and MOAs cannot fulfil their full obligations listed in Schedule 14 Metering Operations as there missing Scenario Variants in the Data Specification preventing them from sending the D0179 to all required Parties.
Stages Selection
I0235 Change Proposal Form
I0235 Change Report (Proposal Plan) V1.0 Approved 04.03.25
I0235 Consolidated Impact Assessment Responses V1.0
R0235 and R0235A Change Report (For Consultation) V1.1
R0235 and R0235A Consolidated Consultation Responses PUBLIC V1.0
R0235 and R0235A Change Report (Final Recommendation) V2.0 (Approved) 01.07.2025
Company Name
-
Review status
Review required
Sequence order of CSS00200 message
Date of latest update
Type
Issue
ID
I0204
Urgent
No
Latest Update
08/11/2024 - The Proposer has withdrawn this issue as it is being progressed under MHHS CR056. The adoption window has now closed. * This is Issue relates to the Market-wide Half Hourly Settlement design.
Summary
Empty
Impacted Consumers
Impacted REC Documents
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Status
Implementation Status
Date Raised
Date of Update to Priority
Solution Development
Stages Selection
Stages Selection
Company Name
St.Clements
Review status
Review required
Schedule 8 Review and Best Practice Guidance Development
Date of latest update
Type
Issue
ID
I0187
Change Category
Change Path
Priority
Urgent
No
Latest Update
26/06/2026 On 25 June 2026, the REC Change Panel approved this extension to plan.
Summary
Schedule 8 - Unbilled Energy Code of Practice has not been reviewed since its development for REC go-live. This Issue seeks to understand if there are any conflicts in the Schedule with best practice and identify any gaps or duplication. Alongside this, a best practice guidance document will be developed which is relevant, complete and aligned to current processes and obligations.
Change Plan
Proposal Plan Approved at Change Panel
Completed
Start:
Due:
Completion:
21 Jan 2025Impacted Consumers
Impacted REC Documents
Impacted REC Parties and Market Participants
Status
Status
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- A new version of Schedule 8.
- Implementation of a new Category 3 guidance document.
Proposed Solution Document
Document title
I0187 - Change Report (Proposal Plan) V1.0 (Pre-Approval) 09.01.2025
Archive
Off
Problem Statement
Schedule 8 - Unbilled Energy Code of Practice has not been reviewed since its development for REC go-live. The Schedule needs to be reviewed to ensure it is up to date, understand if there are any conflicts with best practice and identify any gaps or duplication.
Stages Selection
Stages Selection
I0187 - Change Proposal Form
I0187 - Change Report (Proposal Plan) V1.0 (Approved) 21.01.2025
I0187 - Change Report (Extension to Plan) Approved 17.06.2025
I0187 - Change Report (Extension to Plan) 02.09.2025
I0187 - Change Report (Extension to Plan) 13.01.2025 (Pre-Approval)
I0187 - Change Report (Extension to Plan) V1.0 Approved 25.06.2026
Company Name
Code Manager
Review status
Review required
DPI Extract from CSS
Date of latest update
Type
Change
ID
R0183
Change Category
Change Path
Priority
Urgent
No
Latest Update
11/03/2025 - The proposer has withdrawn the request due to the expected delivery of enquiry data in the same anticipated timescales & the continued pursuance of I0224. The adoption window has closed.
Summary
It has emerged that there are data quality issues relating to the Domestic Premises Indicator (DPI) Data Item, where MPxNs have been recorded as having the wrong DPI. This Change has been raised to identify a mechanism by which this issue can be resolved.
Change Plan
Solution Analysis and Development
In Progress
Start:
11 Jun 2024Due:
20 Sep 2024Completion:
Impacted Consumers
Impacted REC Documents
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- C1 - As a Consumer, I want industry data relating to my energy supply to be accurate, so that I do not experience any issues when switching or engaging with other consumer facing industry practices.
- M1 - As a CSS User, I want available DPI data to be accurate, so that when I engage with industry processes that require DPI data, I am confident that I am engaging with the right information. M2 - As the CSS, I want to provide accurate data to CSS Users, so that I am able to facilitate successful industry operations for my Users.
Problem Statement
Inaccurate DPI data available within industry data sources can result in less accuracy within REC processes that utilise this data, and poorer consumer outcomes. DPI data accuracy needs to be improved to ensure that industry processes and Consumers are not impacted.
Stages Selection
SME
SME Role
Lead Technical Analyst
SME User
maxime.van-eyseren@capgemini.com
SME Role
Lead Assurance Analyst
SME User
vaishnsharma@deloitte.co.uk
Change Proposal Form
R0183 Change Report V3.0 02.12.2024
Company Name
-
Review status
Review required
Improvements to CSS Business Process Logic
Date of latest update
Type
Change
ID
R0178
Change Category
Change Path
Priority
Urgent
No
Latest Update
17/06/2026 - The Code Manager has published an Update to Plan. This will be presented to the REC Technical Expert Panel at their meeting on 24 June 2026.
Summary
This change proposal is aimed towards rectifying a collection of issues that were identified with the CSS Business Process Logic. These have been identified as follows: 1. Deactivation of an active reg. whilst in-flight switch in progress 2. Deactivation of a prior cancelled registration 3. OFAF switch containing multiple MPxN
Impacted Consumers
Impacted REC Services
Impacted REC Parties and Market Participants
Status
Implementation Date
25 June 2027
Implementation Status
Date Raised
Fuel
REC Decision Maker
Date of Update to Priority
Solution Development
Proposed solution summary
- Deactivation of an active reg. whilst in-flight switch in progress As mentioned previously, the ‘Deactivation of an active reg. whilst in-flight switch in progress’ issue did have an existing REC CP raised and therefore is further along the discussion process compared to the other two issues identified. Initial discussion outlined that the most appropriate solution for this change proposal should consider the business needs and the desired outcomes. It was noted that from a business perspective, if the switch has already been accepted, then it should still go through and not be cancelled. Therefore, the following points were raised: • It was acknowledged that there are multiple solution options/approaches that could potentially be employed to resolve this issue. As such, and to avoid being overly prescriptive, it is requested that CSS provider investigate all possible options and outline their recommendation for the most suitable approach, which would be developed/progressed further through the subsequent Impact Assessments. • However, the aim is for an effective solution to be developed which would ensure that the consumer is switched with the original effective date being used and that CSS systems could cater for such registration events whilst following the normal Gate Closure processes. • Where possible, the solution should also look to proactively mitigate the impact of this scenario, as opposed to working on a retrospective basis which can lead to the issue persisting over an extended period of time. It was also noted that consideration would need to be given to state of the meters as this would also have an impact on whether switches are able to progress: Therefore, the following points were raised: • The solution would need to consider how the incumbent supplier has deactivated the meter and whether it has been moved to a ‘terminated’ state or a ‘dormant’ state. o Dormant – The meter is inactive. Note that this is a temporary state and therefore the meter could be put back into service. o Terminated – The meter has reached end of life and cannot be reinstated. Note that this is a permanent state. • If the incumbent supplier has moved the meter into a ‘terminated’ state, the in-flight switch would then need to be cancelled. • However, for the ‘dormant’ state, the following two options would be available in terms of what could happen to the status of the meter and thus the in-flight switch: o Moves from ‘inactive’ to ‘active’ (continue with the switch) o Moves from ‘inactive’ to ‘cancelled’ (cannot continue with the switch)
- Deactivation of a prior cancelled registration and OFAF switch contains multiple of the same MPxN It is noted that the initial approach discussed was to add new Business Data Validation Rules (BDVR) to stop these issues from occurring. However, this was only discussed at high-level and therefore we request that the CSS provider confirm this approach and provide further details as this change proposal progresses.
Problem Statement
1) Deactivation of an active reg. whilst in-flight switch in progress: There are instances where the incumbent supplier is withdrawing prior to the ‘Supply Effective from Date’, causing the accepted switch to fail at Gate Closure which occurs at 17:00hrs. This creates the scenario in which there is no longer a losing supplier for the consumer to switch from, and therefore the switch process stalls and cannot be progressed. Therefore, this has a direct impact on consumers who have a switch request which has already been accepted but CSS is not able to progress further as the switch process stops. Indeed, there have been a total of 82 missing messages observed since 1st January 2023, of which 66 messages have been related to switches where there was no registered Supplier recorded at Gate Closure. The 30th September 2023 Gate Closure was particularly impacted by this scenario and resulted in 45 registrations which did not become effective on 14th October 2023 as planned. It should also be noted that the 1st October is one of the key contracting dates for large Industrial and Commercial (I&C) consumers, consequently increasing the impact to consumers in this instance. 2) Deactivation of a prior cancelled registration: This scenario occurs when the registered supplier of a MPxN (via the active registration) is the same supplier that cancelled a previous switch for the same MPxN. In this case there is the possibility that the supplier could attempt to deactivate the active registration by accidentally providing the cancelled registration identifier. Currently, CSS still accepts the deactivation request and erroneously changes the cancelled registration state from cancelled to inactive, sending out securedInactive messages. Currently, after an MPxN is disconnected, the Supplier is required to submit a deregistration request to CSS. Therefore, there is a possibility that the suppliers could submit this request for a cancelled registration not active registration. CSS would still accept this request as the Business Data Validation Rules (BDVR) lack coverage of this case; in such cases the Supplier may incorrectly believe that they have deregistered the MPANs. 3) OFAF switch containing multiple MPxN: This is the instance where the end user sends through a One Fail All Fail (OFAF) switch with the same MPxN contained within the payload 2 or more times. Multiple registration IDs are created for the same MPxN, and the registration is left in an incorrect state given a lack of appropriate BDVRs. Indeed, there has been a further reported incident regarding an OFAF transaction of the same MPxN. The primary MPxN was associated with a secondary MPxN and therefore two registrations were created for the primary and secondary MPxN, equating to four registrations in total. There was then an objection raised but this only cancelled 1 of the 2 registrations for each MPxN. The remaining 2 registrations proceeded through gate closure.
Stages Selection
SME
SME Role
Lead Technical Analyst
SME User
maxime.van-eyseren@capgemini.com
R0178 - Change Proposal Form
R0178 - Change Report (Proposal Plan) V2.0 (18.02.2025)
R0178 - Update to Proposal Plan V1.0 (Approved) 18.02.2025
R0178 - Consolidated Impact Assessment Responses (Non-Confidential) 18.03.2026
R0178 - Change Report (For Consultation) V1.0
R0178 - Update to Plan (17.06.2026) Pre-Approval
Company Name
REC Technical Services
Review status
Review required