The Great Britain digital energy layer in May 2026: DCC, DSI, MHHS, the SEC and the REC, and how data moves between them

Where the digital layer stands in May 2026

Architecture matters more here than news, but the picture in May 2026 has moved enough in twelve months that a short orientation is the right place to begin. The Market-wide Half Hourly Settlement migration started on 22 October 2025 under BSC Modification P408, reached the M10 to M13 cluster of programme milestones in the first quarter of 2026, and recorded ten million Meter Point Administration Number initiations by mid-quarter; the programme cuts over to the new settlement arrangements in July 2027.^{12 15} The Data (Use and Access) Act 2025 received Royal Assent on 19 June 2025; the Commencement No. 5 Regulations brought Section 138 into force on 6 February 2026, and Commencement No. 6 brought the majority of Part 5's data-protection provisions into force on 5 February 2026, so the legal basis for sector Smart Data schemes is now in force in England, Wales, Scotland and Northern Ireland.^{11 19 20}

The Long Term Development Statement publishes its CIM Stage 2 on 29 May 2026 under the third Ofgem derogation letter of 13 May 2026, which reshaped Stage 2 contents while holding the publication date. Stage 3 publishes on 30 November 2026.³ That date matters here because the LTDS is the first GB instance of a validated, machine-readable distribution model published on a regulator-set cadence, and the data-model approach is expected to spread to transmission and gas in the rest of the decade. The LTDS itself is covered on LTDS explained; the cross-link and the interoperability anchor below tie LTDS to the wider data layer.

Three further moves sit in the May 2026 window. The DCC Smart Meter Communications Licence (SMCL) tender for the successor licensee ran qualification in September and October 2025 and proposals in November 2025; the SMCL itself expires in September 2027, so the successor must take operational handover without service interruption inside the next fifteen months. The DCC ex-ante price control begins in November 2026, replacing the ex-post regime. Ofgem published its final smart-meter rules decision on 30 January 2026, strengthening the operational Licence Condition, introducing a ninety-day in-smart-mode fix obligation, and rolling out Guaranteed Standards of Performance from 23 February 2026. The Energy Smart Data and Privacy Framework, governed by DESNZ and the Department for Energy Security and Net Zero with Ofgem oversight, remains the sector-specific overlay on UK GDPR for energy data.¹⁷

The headline architecture sits on five components in May 2026: the DCC as the meter pipe, the DSI as the federated network for operational and planning data, the MHHS programme as the settlement reform, the SEC and the REC as the multilateral codes, and the DAPF as the privacy overlay. Each component has its own licence, code or statutory base; each has a 2026 to 2030 delivery trajectory; each one's success depends on the others. The sections that follow walk each one in turn and then tie them together at the CIM interoperability anchor.

The DCC: licence, architecture and the service-request walk

The Data Communications Company sits inside a single statutory frame: the Smart Meter Communications Licence (SMCL), held by Smart DCC Ltd as a wholly owned subsidiary of Capita plc. The SMCL was issued in 2013 and expires in September 2027. Schedule 16 of the Data (Use and Access) Act 2025 makes the smart-meter communications regime statutory in the latest revision, updating earlier provisions; the Act consolidates the smart-meter communications duty with the wider Smart Data architecture that the DUA Act puts in place.¹⁶ Ofgem regulates the SMCL through the Smart Meter Transition and Data Communications Company programme; the successor licensee tender ran qualification in September and October 2025 with closing proposals in November 2025.

The DCC is a pipe by design. Most readings pass through the DCC without the DCC having read access; the end-to-end cryptography between the meter and the supplier sits inside the SMKI (Smart Metering Key Infrastructure) band, and the DCCKI (DCC Key Infrastructure) band wraps the supplier-facing transport with TLS and organisation certificates. The DCC Data Service Provider (DSP) is the central message broker. It authenticates the supplier, applies routing rules from the SEC, signs the outbound message, and hands the encrypted payload to the regional Communications Service Provider (CSP). Two CSPs split GB: Arqiva covers the North region (Scotland and northern England, approximately thirty percent of premises) using long-range mesh radio at 412 MHz; Virgin Media O2 covers Central and South (approximately seventy percent of premises) using cellular and short-range mesh. The DCC network coverage obligation is no less than 99.25 percent of premises minimum.

At the premise, the Communications Hub translates from the WAN side to the Home Area Network. The dual-band Communications Hub adds an 868 MHz secondary band for thick-walled and multi-storey homes, lifting HAN coverage from approximately seventy percent under single-band hardware to about 96.5 percent under the dual-band design. The HAN runs Zigbee Smart Energy Profile (SEP) at 2.4 GHz primary plus 868 MHz secondary; pairs the Communications Hub to the SMETS2 Electricity Smart Metering Equipment (ESME), Gas Smart Metering Equipment (GSME), the In-Home Display (IHD), and any Prepayment Meter Interface Device (PPMID) or authorised Consumer Access Device (CAD). The application protocol used over the radio path is DLMS/COSEM, defined to a fine grain in the DCC User Interface Specification (DUIS).

The DSP modernisation that began in 2025 is the largest single change in the DCC architecture since the original 2018 rollout. CGI, IBM UK, Netcompany and Vodafone hold the modernisation contracts under sub-contract to the DCC. The PKI-E Programme is the parallel cryptographic refresh: the Trusted Service Provider contract was extended through 2025, and certificate lifetime was extended to fourteen years to align with the Root Certificate Authority lifetime. Virtual WAN (VWAN), which uses the consumer's broadband router with their consent to reach the approximately one percent of premises with no Arqiva or Virgin Media O2 signal, launches in 2026 as the answer to the residual coverage gap.

Ofgem's final smart-meter rules decision of 30 January 2026 strengthened the operational Licence Condition, introduced a ninety-day in-smart-mode fix obligation on suppliers, and rolled out Guaranteed Standards of Performance from 23 February 2026; the three GSOPs provide automatic compensation to domestic consumers when a supplier misses the six-week installation-appointment offer, the in-smart-mode fix duty, or the five-working-day smart-mode-fault assessment. The Energy Smart Data and Privacy Framework (DAPF) sits over UK GDPR for the data the DCC carries; the privacy section below treats it at depth.¹⁷

Smart-meter coverage at the end of 2025 was forty one million smart and advanced meters installed (about seventy one percent of all GB meters), with more than thirty seven million operating in smart mode or classified as advanced. Approximately 2.8 million were installed in calendar 2025, a 5.8 percent reduction on 2024. About 11.3 percent of domestic smart meters operate in prepayment mode. Eleven million SMETS1 meters now operate on DCC central systems after migration; the residual SMETS1 cohort is the Mid-Operational Cohort (MOC, Secure), for which the DCC consulted on a decommissioning timetable in July and August 2025 and for which the regulatory framework for SMETS1 enrolment expired at the end of 2025. The Radio Teleswitch Service (RTS), the legacy BBC long-wave signal used by some heating-control meters in Scotland and rural England, began phased switch-off on 30 June 2025; approximately three hundred thousand RTS meters required replacement in mid-2025, with about one hundred and five thousand in Scotland.

The four-domain Data Sharing Infrastructure

The Data Sharing Infrastructure is the second working component of the digital energy layer, alongside the DCC. The DSI is federated rather than central: each participant runs a Data Preparation Node (DPN) at its boundary; the central Data Sharing Mechanism (DSM) holds the metadata catalogue and brokers authentication; no data is stored centrally; all exchanges are peer to peer between DPNs. The Trust Framework is the legal and technical layer that replaces hundreds of bilateral data sharing agreements with standardised terms, risk profiles and user attributes. Ofgem's DSI Governance Decision OFG1164 of March 2025 set the three-tier governance: Ofgem as regulator, the Interim DSI Coordinator (NESO, appointed 1 April 2025) as operator, and the Stakeholder Advisory Group as industry voice.⁴

The DSI reads as a four-domain architecture rather than a single network, because each domain has a distinct regulatory base, a distinct set of participants, and a distinct release trajectory. The four domains are the regulated-network domain (DNOs, transmission owners, NESO under their licence conditions), the market and settlement domain (Elexon as Market Facilitator from December 2025, the BSC code body), the consumer and retail domain (suppliers, RECCo, the Consumer Consent Solution), and the third-party access domain (authorised participants under the Energy Smart Data scheme established under the DUA Act 2025). The DPN sits at the boundary of every participant in every domain; the DSM brokers across domains; the Trust Framework holds the cross-domain legal-and-technical basis.

The lifecycle runs discovery, alpha, beta (private then public), then live. The Minimum Viable Product is currently scoped to regulated networks and digitally-ready organisations, with the Connections Reform use case as the headline first MVP application. Public beta and live releases are planned for 2028 to 2030. Initial use cases for MVP delivery are Outage Planning (the pilot demonstrator that ran from September 2024), Connections Reform (the MVP target), and a post-MVP queue that includes Smart Secure Energy Systems and Flexibility Market Asset Registration. Funding flows through NESO's RIIO-IT pot during the Interim Period; Ofgem committed to assess alternative funding models after 2028.⁸

The four domains separate cleanly because the boundary between them is also a boundary between regulators and code bodies. The regulated-network domain answers to Ofgem under SLC obligations, the Data Best Practice Guidance and (for distribution) the LTDS direction. The market and settlement domain answers to the BSC code body and (since December 2025) the Elexon Market Facilitator that absorbed the Open Networks legacy. The consumer and retail domain answers to RECCo under the REC and the SEC (for metering data) and the Consumer Consent Solution that RECCo is delivering with an MVP launch in late 2026. The third-party access domain answers to the Energy Smart Data scheme rules under the DUA Act 2025; the legal-base architecture is modelled on Open Banking but distinct in its parent regime. Each domain has its own set of trustworthiness profiles within the Trust Framework; common attributes describe data publisher and consumer trust levels and anchor each profile to a common accreditation.

NESO as Interim DSI Coordinator carries a 2028 sunset on the appointment. Ofgem instructed NESO to draft the first version of the architectural reference framework by end of August 2026, then consult. The DSI roadmap interlocks with the LTDS data layer (handled below), the MHHS settlement reform (handled in the next section), and the Open Networks legacy that Elexon Market Facilitator absorbed in December 2025. The DSI is the cross-cutting infrastructure that any future GB energy-data initiative will federate on; the LTDS data layer is the first GB instance of a regulator-mandated CIM-based data model published on the same cadence the DSI is expected to standardise across the other domains over 2028 to 2030.

The data-sharing rulebook: Data Best Practice and the Triage Playbook

The data-sharing rulebook in GB sits inside Ofgem's Data Best Practice Guidance, embedded in a Special Licence Condition introduced under RIIO-2 ("Digitalisation") that binds Gas Distribution, Gas Transmission, Electricity Transmission, Electricity Distribution, the Electricity System Operator and the Gas System Planner licences. Data Best Practice has eleven principles. The defining one is Principle 11: presumed open. Every Data Asset, its Metadata and the Software Scripts used to process it are presumed open by default; the data custodian must provide objective justification if openness is restricted. Version 3.5 (June 2025) updated the terminology from "Licensee/s" to "Obligated Party/ies" so the guidance can extend beyond network licensees to code bodies via licence modification and consequential code changes; Principles 3, 5, 9 and 11 received updated text and intended-outcome statements.

The Data Triage Playbook, refreshed in 2024 by the ENA's Data and Digitalisation Steering Group, operationalises Principle 11. It identifies five categories of legitimate barrier to openness: privacy, security, negative consumer impact, commercial sensitivity, and legislation or regulation. For each, the data owner must apply the least-impact mitigation (data modification, aggregation, suppression) before defaulting to closed. The triage decision and the rationale must be transparent. The Playbook is the canonical worked example of how presumed-open works as a regulatory pattern, because it turns the presumption into a documented decision rather than a declaration.¹⁰

The worked example for presumed-open at scale is the Embedded Capacity Register (ECR). Formerly the System Wide Resource Register, the ECR was renamed in July 2020 via DCUSA modification DCP 350. The licence basis is Standard Licence Condition 50 on the Electricity Distribution Licence. Each DNO and IDNO publishes its register on its own website on a monthly cadence (within ten working days of each calendar month-end), to a schema agreed through the Open Networks programme. The threshold is at or above 1 megawatt for generation or storage capacity (import or export); some operator portals apply a 50 kilowatt threshold for visibility. Published fields cover the customer name, project location, connection substation, point of connection voltage, capacity, technology type, connection status, and flexibility service participation. The ECR is the foundation for Connections Reform analysis and any third-party flex-market participation feasibility study.

The Open Networks programme itself concluded with a webinar on 3 July 2025 after eight years (2017 to 2025). All UK network companies participated. The tangible legacy that Elexon as Market Facilitator absorbed in December 2025 includes aligned flexibility products (Sustain, Secure, Dynamic, Restore), common settlement processes, dispatch APIs, baselining methodology, the ECR format, and the local-flexibility headline: contracted local flexibility rose from about 3.2 gigawatts in 2024 to about 9 gigawatts contracted in 2025 from 31 gigawatts tendered.¹⁰ The Elexon Market Facilitator is the formal successor body, going live in December 2025 with the BSC code-body relationship and the inherited interoperability artefacts.

This rulebook is the policy substrate of the DSI architecture above. The DSI is the federated mechanism; the Data Best Practice Guidance is the obligation; the Triage Playbook is the operational decision pattern. The two together give the GB energy data layer a presumed-open default with a documented exceptions process, which is the working pattern that the DUA Act 2025 widens to third-party access through the Energy Smart Data scheme. NESO's Future Energy Scenarios, the Strategic Spatial Energy Plan and the Centralised Strategic Network Plan all publish into this rulebook; the SSEP methodology was published in May 2025, with the first SSEP iteration due in Q4 2026 and the final SSEP in Autumn 2027.^{13 14}

MHHS: P408, migration milestones and the July 2027 cutover

The Market-wide Half Hourly Settlement (MHHS) programme moves every electricity meter point to half-hourly settlement. The Ofgem decision to mandate the move was published in April 2021. The legal mechanism is BSC Modification P408, which carries the consequential changes to the Balancing and Settlement Code, the BSC Code Subsidiary Documents (CSDs) and the Service Description and Service Description User Interface specifications. Elexon was appointed Implementation Manager in 2022. The programme operates a numbered milestone framework from M1 through M16; the operational migration window started on 22 October 2025 (M10) and runs to cutover at M16 in July 2027.^{12 15}

In May 2026 the programme sits inside the M10 to M13 cluster of milestones. Migration began on 22 October 2025 at M10 with suppliers initiating the move of MPANs to half-hourly settlement. Recent Elexon reporting recorded ten million MPAN initiations completed during the first quarter of 2026, with more than two million meters fully transitioned to half-hourly settlement by mid-February 2026. The migration rate has to lift through the remainder of 2026 to keep the M14 readiness gate around October 2026 (approximately eighty percent migrated, with the Insights Solution publishing aggregated MHHS data from that point), and the M15 full-implementation date in May 2027, before the M16 cutover in July 2027.¹²

The steady-state run rate of the post-cutover settlement system is the headline number that gives MHHS its strategic weight. Elexon will process up to five hundred billion half-hourly readings per year once the migration is complete. The Electricity Networks Strategic Framework analysis put consumer-led-flexibility infrastructure savings at forty to fifty billion pounds cumulative across 2021 to 2050 (2020 prices), conditional on MHHS landing. The savings come from the move from monthly to half-hourly settlement of every meter point, which prices flexibility at the half-hour rather than averaging it across the month, and which lets a supplier offer Time of Use tariffs to every consumer rather than only to a Time of Use cohort.

The MHHS data flow lifts the settlement chain off the legacy Data Collection and Aggregation regime. Half-hourly readings flow from the meter through the HAN to the Communications Hub, over the WAN through the relevant CSP, through the DCC Data Service Provider, and out to the supplier or to a Smart Data Service appointed under the new MHHS arrangements. The supplier or Smart Data Service feeds the readings to the settlement engine through Elexon's data services. The new arrangements introduce three Smart Data Service roles: the Lead Supplier role, the Half Hourly Data Service role, and the Unmetered Half Hourly Data Service role. Each role is licensed under the BSC; each role's interface specification is published on the MHHS programme portal.

The relationship between MHHS and the DSI is the obvious cross-reference for the next two years. MHHS produces the half-hourly settlement data; the DSI Operational tier carries operational data on the minute-to-hour scale; the planning tier carries the LTDS, Future Energy Scenarios, Distribution Future Energy Scenarios and ECR. The MHHS programme cutover in July 2027 sits one year after the August 2026 deadline that Ofgem set for NESO as Interim DSI Coordinator to draft the first version of the DSI architectural reference framework. The two programmes are independent in delivery but interlocked in operational use: the half-hourly settlement run after MHHS cutover is one of the largest single data flows that any DSI-mediated use case will need to consume, and the Insights Solution that succeeds the legacy BMRS (which was retired on 31 May 2024) is the operational-tier feed that the DSI MVP and post-MVP use cases will federate against.⁹

The SEC and the REC: two multilateral codes that hold the layer together

Two multilateral codes hold the digital energy layer together at the metering and switching level. The Smart Energy Code (SEC) is the multilateral agreement among suppliers, network operators, manufacturers and the DCC, administered by the SEC Administrator and Secretariat (SECAS) and held by the Smart Energy Code Company (SECCo). The Retail Energy Code (REC) is the multilateral code that replaced the Master Registration Agreement (MRA) and the Supply Point Administration Agreement (SPAA) in 2019, held by the Retail Energy Code Company (RECCo). The Energy Act 2023 changed the parent regime for both codes: Ofgem now selects and licenses code managers under the Code Manager Selection Regulations 2024.

The SEC binds anyone who reads or writes data through the DCC pipe. It covers SMETS2 device specifications, the DCC User Interface Specification (DUIS), the security regime (SMKI and DCCKI), the operational performance regime, the threshold anomaly detection (TAD) provisions for prepayment top-up integrity, the consumer access provisions (CAD authorisation), and the dispute resolution machinery. The SEC has a Modifications Panel that holds regular working groups; a SEC Modification is the mechanism by which any change to the metering data flows is approved. The SECCo is invited to be the code-manager candidate under the Energy Act 2023 framework; standard licence conditions were consulted on in May and June 2025.¹⁸

The REC is the code body for the switching architecture that replaced the legacy MRA plus SPAA stack and the multiple isolated Distribution Network Operator, Independent Distribution Network Operator, Gas Transporter and Independent Gas Transporter registries. REC v1.0 was published in 2019; REC v2.0 went live alongside the Central Switching Service (CSS) operated by the DCC in September 2022. The CSS holds the central registration master for both electricity (MPAN) and gas (MPRN) supply points. Switching completion target is next working day. The CSS has processed approximately thirty seven million switches by mid-2025 since its July 2022 go-live, on the DCC reporting. REC modifications continue through 2025 and 2026; Ofgem confirmed RECCo as the code-manager candidate under the Energy Act 2023 framework.¹⁸

The Consumer Consent Solution (CCS) is the consent layer that RECCo is delivering under the REC. The Minimum Viable Product launches in late 2026; the Minimum Marketable Product (MMP) covers domestic consumers only and provides a data-source-agnostic single consent dashboard. Where a party accesses data via Elexon's Smart Data Repository (the MHHS-era data service) and consumer consent is required, CCS use is mandatory. The API technical specification draft was scheduled for summer 2026 with early adopters in Q2 and Q3 2026. The CCS sits on top of the Data Access and Privacy Framework (DAPF) at the consumer-data layer; the privacy section below treats the DAPF.

How the two codes interlock with each other and with the DCC

The SEC and the REC are both multilateral and both bound on the same SMCL-licensed central infrastructure (the DCC), but they serve different parts of the flow. The SEC covers the metering data path (the service-request walk in the diagram above): supplier head-end through the DCC Data Service Provider, through the regional CSP, through the Communications Hub, to the meter and back. The REC covers the registration path: the gaining supplier submits the switch to the CSS; the CSS holds the MPAN and MPRN master and notifies the losing supplier; the next-working-day completion target sits inside the REC. Both codes refer to the same underlying device population (the smart meter cohort), but a SEC Modification touches the DUIS, the device profile or the operational security regime; a REC Modification touches the registration data, the switching SLAs, or the consent layer.

The two codes are the consumer-side and the data-side of the same architecture. The SEC governs the technical and security path the data travels; the REC governs the relationship and consent context within which a supplier can read or write that data. Where they meet (at the supplier head-end and at the CCS) is where the operational risk sits in 2026: a switching event under the REC triggers a SEC-governed re-pairing of the device population with the new supplier, the previous supplier's authorisations have to be revoked, and the DCC has to update the routing tables so that the next service request from the new supplier reaches the right meter. The smoothness of that handoff is what the GSOPs from 23 February 2026 are designed to guarantee for domestic consumers.

Privacy: the Energy Smart Data and Privacy Framework

The Energy Smart Data and Privacy Framework (DAPF) is the sector-specific overlay on UK GDPR for energy data. DESNZ owns the policy framework; Ofgem regulates the licensee obligations that put the framework into force; the Information Commissioner is the data-protection regulator. The DAPF sets purpose limitation by default and grades consumer consent for granular data: the default for a domestic consumer is monthly granularity with an opt-in for daily or half-hourly; microbusinesses can opt out of any granularity finer than monthly. The "Data Guide for Smart Meters" (Energy UK and Citizens Advice, 2013, updated since) is the consumer-facing Privacy Charter document.^{17 8}

The Data (Use and Access) Act 2025 (Royal Assent 19 June 2025) widens the legal base for third-party access. Section 138 of the Act and the majority of Part 5's data-protection provisions were brought into force by the Commencement No. 5 Regulations (SI 2026/31, in force 6 February 2026) and the Commencement No. 6 Regulations (SI 2026/82, the majority of Part 5 in force 5 February 2026), so the legal basis for sector Smart Data schemes is now operational in England, Wales, Scotland and Northern Ireland.^{11 19 20} The Energy Smart Data scheme, governed under the new Act, is modelled on Open Banking but distinct in parent regime: a domestic consumer can authorise a third party to read their meter data for a defined purpose, the authorisation flows through the Consumer Consent Solution, and the third party operates as a Data Preparation Node in the consumer and retail domain of the DSI architecture.

Ofgem's Consumer Consent Solution decision of 29 April 2025 is the foundation for the CCS rollout. The DESNZ Energy Smart Data government response was published in July 2025: seventy five percent of consultation respondents wanted functional responsibilities held by a central body; the Government response confirms the framework approach. The Open Banking comparator that DESNZ cites (over three hundred authorised providers, eleven million users, two billion pounds private investment, four thousand eight hundred jobs) sets the policy benchmark; the energy comparator will follow a similar curve but on a smaller initial base because the metering data population is smaller than the open-banking customer base.

Theft detection is the other privacy-adjacent capability the smart-meter system adds. Stay Energy Safe (operated for the industry by Crimestoppers) is the public reporting line; TRAS (the Theft Risk Assessment Service) uses smart-meter consumption data to identify probable-theft patterns and is governed under the SEC. The smart-meter cohort tightens theft detection but adds new attack surfaces (meter tamper, comms-hub spoofing); the CPA (Commercial Product Assurance) scheme run by the NCSC since 2012 governs the security characteristics of ESME, GSME and Communications Hub devices and is the assurance mechanism for that risk. The NCSC published "handing over the baton of smart meter security: a decade of progress" in 2024; operational ownership has been moving to industry while the NCSC retains an advisory role.

The LTDS data layer and the CIM interoperability anchor

The Long Term Development Statement is the standardised, machine-readable model of the distribution network that every DNO publishes under Standard Licence Condition 25.2 of the Electricity Distribution Licence.¹ The 30 April 2024 Ofgem Direction moved the LTDS from Excel files to a validated Common Information Model (CIM) data model, with phased delivery across Stages 1, 2 and 3. The first derogation letter of March 2025 introduced the Heatmap Extension; the second held the Stage 2 contents at consultation; the third derogation letter of 13 May 2026 reshaped Stage 2 contents while holding the publication date.^{2 3} Stage 2 publishes on 29 May 2026; Stage 3 publishes on 30 November 2026. The LTDS data layer is the first GB instance of a validated, machine-readable network model published on a regulator-set cadence. The model, the validation pipeline, the mRID resolution rules and the SHACL profile are covered in depth on LTDS explained; the cross-link and the interoperability frame are anchored below.

The interoperability frame is the Common Information Model published by IEC TC 57. The base is IEC 61970-301 (the CIM base for the EMS-API), with Amendment 1 of 2022 now consolidated into the published Edition 7.⁷ The distribution-network extensions are IEC 61968-13 (the CDPSM, the Common Distribution Power System Model, BS EN IEC 61968-13:2021 Edition 2.0); these are the profiles GB DNOs use for the unbalanced distribution case.⁶ The transmission interchange profile is CGMES (the Common Grid Model Exchange Specification), at version 3 in 2026, with the ENTSO-E Application Profiles Library v1.1.1 patch of 7 October 2025 as the current operational reference. The BSI hosts the CIM Engagement Hub at https://cim.bsigroup.com/, which is the UK governance portal for the CIM profile work and the place an authorised participant registers their profile contributions.⁵

The cross-cutting reading is that the LTDS data layer is the precedent the rest of the GB digital energy layer will follow. The LTDS direction sets a regulator-mandated, schedule-bound, validated CIM-based publication on a defined cadence. The DSI roadmap (above) federates that pattern across the four domains. The MHHS programme (above) shifts the settlement run onto a half-hourly cadence that any DSI-mediated use case will consume. The SEC and the REC (above) hold the metering and switching codes on the same DCC-licensed central infrastructure that produces the data the LTDS layer publishes. The DAPF (above) sets the privacy floor on the consumer-data layer. The CIM Engagement Hub at BSI is the interoperability anchor that ties the model work to the BSI's wider digital standards portfolio.

Two strategic plans interact with this anchor at the level of the operating model. NESO's Strategic Spatial Energy Plan (SSEP), with first iteration in Q4 2026 and final SSEP in Autumn 2027, depends on the LTDS Stage 2 and Stage 3 model as the planning data substrate for any distribution-level work it carries.¹³ The Centralised Strategic Network Plan (CSNP), with methodology approved by Ofgem in April 2026, the transitional T-CSNP due in June 2026, and the first full CSNP due by end-2028, depends on the same data substrate for the transmission-distribution interface.¹⁴ The publishing cadence Ofgem set for the LTDS in 2024 is in 2026 the working model that the SSEP and the CSNP federate against. The CIM interoperability anchor at the BSI Engagement Hub is the standards substrate that holds all four together.⁵

The digital energy layer in May 2026 resolves to five working components on one substrate. The DCC is the meter pipe. The DSI is the federated cross-domain network. The MHHS programme is the settlement reform. The SEC and the REC are the multilateral codes. The DAPF is the privacy overlay. The LTDS data layer is the published model that the other four federate against. The CIM is the interoperability anchor. In twelve months the layer will look very similar in shape and very different in coverage: MHHS will be past its M14 readiness gate; the DSI MVP for Connections Reform will be live in some form; the LTDS Stage 3 publication will be out; the DCC successor licensee will be in operational handover; the CCS MVP will be in early adopter use. The LTDS data-layer cross-link on LTDS explained carries the deepest treatment of that model; the rest of the layer derives much of its 2026 to 2030 trajectory from the publishing pattern that LTDS established in 2024 and that the third derogation letter holds in 2026.