NESOOFGEMDESNZ

Connection and Use of System Code

All modifications to the Connection and Use of System Code, tracked through their lifecycle. Administered by NESO.

How CUSC modifications work

The Connection and Use of System Code (CUSC) is the commercial rulebook for transmission access in Great Britain. It governs connection charges, Transmission Network Use of System (TNUoS) charges, Balancing Services Use of System (BSUoS) charges, capacity allocation, and the terms under which generators, suppliers, and interconnectors connect to and use the transmission network. NESO administers the code.

The modification process

Anyone connected to or seeking connection to the transmission system can propose a CUSC modification. Proposals go to the CUSC Modifications Panel, which assigns them to a Workgroup. The Workgroup develops the solution, often producing alternative proposals alongside the original. After a Code Administrator Consultation, a Final Modification Report goes to the Panel, which votes on the original and any alternatives. The Panel recommends to Ofgem, which makes the final decision.

Key concepts

  • TNUoS (Transmission Network Use of System) charges are the largest component. They signal where on the network generation and demand should locate. Charging methodology changes are some of the most contested modifications.
  • Self-Governance applies when a modification will not materially affect consumers, competition, or existing contractual arrangements. The Panel decides; parties can appeal.
  • Send Back means Ofgem has returned the modification to the Workgroup for further work, rather than approving or rejecting it.
  • Alternatives are common. Workgroups often produce multiple solutions, and the Panel votes on each. This means a single CMP number can have several competing proposals.
189 shown
GovernanceStageRaised
TBCRaised25 Feb 2026
CMP467Removal of outdated references in CUSC (charging)
Open pagealso affects STC
TBCRaised25 Feb 2026
CMP468Removal of outdated references in CUSC (non-charging)
Open pagealso affects STC
Standard (direct)Rejected13 Dec 2025
CMP450Introducing the definition of Dynamic Reactive Compensation Equipment (DRCE) in the CUSC
also affects CMP418
StandardWorkgroup2 Dec 2025
CMP466CMP456 Consequential Charging Modification
Open pagealso affects CMP456
Fast TrackDecision13 Nov 2025
CMP464Section 14 Corrections
Open page
Standard (direct)Withdrawn13 Nov 2025
CMP465Construction Progression Milestones (M5-M8) Neutrality
Self-Governance (direct)Implementation31 Oct 2025
CMP463Stabilising the Specific Onshore Expansion Factors from 1st April 2026
Open page
UrgentImplemented24 Oct 2025
CMP462Provision for Alternate Panel Members
Fast TrackImplemented16 Oct 2025
CMP461Rectifications to Legal Text following various implementations
StandardWorkgroup8 Aug 2025
CMP460Improving Transmission Connection Asset Charging
Open pagealso affects DCP461
TBCWithdrawn6 Aug 2025
CMP458Prorating of transmission residual demand charges
also affects TBC
StandardWorkgroup11 Jul 2025
CMP457Revision of the Obligatory Reactive Power Service (ORPS)
Open page
TBCWorkgroup19 Jun 2025
CMP456Cost recovery for legacy plant in relation to GC0168
Open pagealso affects GC0168
UrgentImplemented10 Jun 2025
CMP454CMP434/CMP435 Section 11 Changes
Fast TrackImplemented10 Jun 2025
CMP455Minor Amendments to the CUSC following implementation of CMP434/ CMP435
StandardDecision30 Apr 2025
CMP453To Bill BSUoS on a net basis at BSC Trading Units
Open page
UrgentWithdrawn27 Feb 2025
CMP452Suspension of TNUoS Payments for generators connecting during the 2024/25 charging year
also affects CMP445
TBCRejected19 Feb 2025
CMP451Suspending TNUoS payments when TOs and/or NESO has delayed connection date
Fast TrackImplemented13 Feb 2025
CMP449Rectifications to pending 01 April 2025 implementation legal text
also affects CMP382, CMP408, CMP411, CMP424 and CMP430
UrgentImplemented7 Feb 2025
CMP448Introducing a Progression Commitment Fee to the Gate 2 Connections Queue
also affects CMP434/CMP435
StandardImplemented17 Jan 2025
CMP447Removal of designated strategic works from cancellation charges/securitisation
also affects CMP428 / STC CM094
UrgentImplemented14 Jan 2025
CMP446Increasing the lower threshold in England and Wales for Evaluation of Transmission Impact Assessment (TIA)
also affects CMP434/CMP435
UrgentWorkgroup8 Nov 2024
CMP445CMP445 Pro-rating first year TNUoS for Generators
Open page
UrgentRejected21 Oct 2024
CMP444CMP444 Introducing a cap and floor to wider generation TNUoS charges
Standard (direct)Implemented8 Oct 2024
CMP443Removing references to “Fax” or “Facsimile” within the CUSC
also affects STC and Grid Code
StandardWorkgroup23 Sept 2024
CMP442Introducing the option to fix Generator TNUoS charges
Open page
Standard (direct)Workgroup12 Sept 2024
CMP441Reducing the credit risk of supplying non-embedded hydrogen electrolysers
Open page
StandardWorkgroup14 Aug 2024
CMP440Re-introduction of Demand TNUoS locational signals by removal of the zero-price floor
Open pagealso affects SQSS
Withdrawn18 Jul 2024
CMP439This modification proposal would remove the requirement for ≤100 MW licenced embedded generators to have a Bilateral Embedded Generator Agreement (BEGA) before participating in the Balancing Mechanism.
Implemented10 Jun 2024
CMP438This modification is to make some minor clarifications and corrections to the Connection and Use of System Code (CUSC) paragraph 14.25, which provides an illustrative example of a Transmission Network Use of System charge (TNUoS) demand reconciliation. It does not affect users’ charges.
Standard (direct)Implemented9 May 2024
CMP436Update CUSC arrangements to replace the Electricity Arbitration Association (EAA) with the London Court of International Arbitration (LCIA) (Non-Charging)
Standard (direct)Implemented9 May 2024
CMP437Update CUSC arrangements to replace the Electricity Arbitration Association (EAA) with the London Court of International Arbitration (LCIA) (Charging)
UrgentImplemented19 Apr 2024
CMP434Implementing Connections Reform
also affects STC (CM095)
UrgentImplemented19 Apr 2024
CMP435Application of Gate 2 Criteria to existing contracted background
also affects STC (CM096)
StandardWorkgroup11 Apr 2024
CMP433Optimised Transmission Investment Cost model (OpTIC)
Open page
UrgentRejected11 Mar 2024
CMP432Improve “Locational Onshore Security Factor” for TNUoS Wider Tariffs
UrgentImplemented16 Feb 2024
CMP430Adjustments to TNUoS Charging from 2025 to support the Market Wide Half Hourly Settlement (MHHS) Programme’
UrgentWithdrawn16 Feb 2024
CMP431Adjustments to TNUoS Charging from 2025 to support the Market Wide Half Hourly Settlement (MHHS) Programme (Non-Charging)’
UrgentImplemented11 Jan 2024
CMP428User Commitment liabilities for Onshore Transmission circuits in the Holistic Network Design
Fast TrackImplemented11 Jan 2024
CMP429Typographical and formatting updates following the implementation of CMP376 (Inclusion of Queue Management process within the CUSC)
UrgentImplemented13 Dec 2023
CMP427Update to the Transmission Connection Application Process for Onshore Applicants
StandardWorkgroup30 Nov 2023
CMP426TNUoS charges for transmission circuits identified for the HND to add capacity across boundaries
Open page
UrgentImplemented24 Oct 2023
CMP425Billing Demand Transmission Residual By Site
N/ARejected12 Oct 2023
CMP421CUSC Section 14 – Housekeeping changes update
also affects N/A
N/ARejected12 Oct 2023
CMP422CUSC Non-Charging Housekeeping changes update
also affects N/A
StandardDecision12 Oct 2023
CMP423Generation Weighted Reference Node
Open page
StandardImplemented12 Oct 2023
CMP424Amendments to Scaling Factors used for Year Round TNUoS Charges
also affects SQSS
StandardWithdrawn14 Sept 2023
CMP420Treatment of BSUoS Revenue Recovery and creation of a BSUoS Fund
StandardWorkgroup10 Aug 2023
CMP419Generation Zoning Methodology Review
Open page
StandardRejected2 Aug 2023
CMP418Refine the allocation of Dynamic Reactive Compensation Equipment (DRCE) costs at OFTO transfer
also affects N/A
StandardWorkgroup12 Jul 2023
CMP417Extending principles of CUSC Section 15 to all Users
Open pagealso affects STC and STCP
StandardImplemented11 Jul 2023
CMP415Amending the Fixed Price Period from 6 to 12 months
also affects CUSC (CMP361 / CMP362) and CMP408
N/ARejected11 Jul 2023
CMP416Amending the Fixed Price Period from 6 to 12months with two seasonal tariffs
also affects N/A
StandardWorkgroup13 Apr 2023
CMP414CMP330/CMP374 Consequential Modification
Open pagealso affects CUSC (CMP330/ CMP374) and STC (CM079)
StandardRejected16 Mar 2023
CMP413Rolling 10-year wider TNUoS generation tariffs
Self-Governance (direct)Implemented9 Feb 2023
CMP410Payment Timescales for Monthly Payments
StandardImplemented9 Feb 2023
CMP411Introduction of Anticipatory Investment (AI) within the Section 14 charging methodologies.
also affects CUSC (CMP402)
Standard (direct)Implemented9 Feb 2023
CMP412CMP398 Consequential Charging Modification
also affects Grid Code (GC0148 and GC0156), CUSC (CMP398), SQSS (GSR032), STC (CM089 and STCP PM0128)
StandardImplemented12 Jan 2023
CMP408Allowing consideration of a different notice period for BSUoS tariff settings
also affects CUSC (CMP361 / CMP362)
Implemented12 Jan 2023
CMP409As part of their decision on CMP363, Ofgem identified 2 changes that need to be made ahead of CMP363 implementation on 1 April 2023
Rejected22 Nov 2022
CMP406 and CMP407Seeks to provide an option for an ex ante fixed BSUoS tariff with a 12 month fixed period, 3 month notice period, and a P85 level BSUoS fund. CMP406 addresses the charging changes and CMP407 addresses the consequential definition changes
StandardWorkgroup10 Nov 2022
CMP402Introduction of Anticipatory Investment (AI) principles within the User Commitment Arrangements
Open pagealso affects CUSC (CMP411)
Standard (direct)Implemented10 Nov 2022
CMP403Introducing Competitively Appointed Transmission Owners & Transmission Service Providers (Section 14)
also affects Grid Code (GC0159), STC (CM086/CM087) and SQSS (GSR031)
Standard (direct)Implemented10 Nov 2022
CMP404Introducing Competitively Appointed Transmission Owners & Transmission Service Providers (Section 11)
also affects Grid Code (GC0159), STC (CM086/CM087) and SQSS (GSR031)
StandardWorkgroup10 Nov 2022
CMP405TNUoS Locational Demand Signals for Storage
Open pagealso affects CUSC (CMP393)
Implemented13 Oct 2022
CMP399Seeks to make minor amendments to CUSC Section 14
Implemented13 Oct 2022
CMP400Seeks to make minor amendments to CUSC which sit outside of Section 14
Implemented13 Oct 2022
CMP401As a result of CMP318, the period by which Meter Point Administration Numbers (MPANs) in Measurement Classes F and G are treated as NHH for TNUoS was extended to 31 March 2023. CMP401 seeks to amend this date to align with Milestone 15 (M15) of the Market Wide Half Hourly Settlement (MHHS) Programme and relevant subsequent charging year.
Standard (direct)Decision15 Aug 2022
CMP397Consequential changes required to CUSC Exhibits B and D to reflect CMP316 (Co-Located Generation Sites)
Open pagealso affects CUSC (CMP316)
StandardImplemented15 Aug 2022
CMP398GC0156 Cost Recovery mechanism for CUSC Parties
also affects Grid Code (GC0148 and GC0156), CUSC (CMP412), SQSS (GSR032), STC (CM089 and STCP PM0128)
Standard (direct)Rejected11 Aug 2022
CMP396Re-introduction Of BSUoS on Interconnector Lead Parties
Implemented11 Aug 2022
CMP395Seeks to cap BSUoS per Settlement Period from 1 October 2022 (or such later date as the Authority may specify) to 31 March 2023, recoup the money in charging year 2023/24; and cap the liability to be carried by the ESO
StandardRejected9 Jun 2022
CMP393Using Imports and Exports to Calculate Annual Load Factor for Electricity Storage
also affects CUSC (CMP405)
Withdrawn9 Jun 2022
CMP394Seeks to exempt electricity storage assets in positive Transmission Network Use of System zones from payment of generation charges. Here, ‘electricity storage’ refers to all storage that has booked Transmission Entry Capacity (i.e. pumped and battery)
StandardImplemented27 May 2022
CMP392Transparency and legal certainty as to the calculation of TNUoS in conformance with the Limiting Regulation
Implemented23 May 2022
CMP391Seeks to ensure there is a definition of “Charges for Physical Assets Required for Connection” which reflects the Limiting Regulation, in light of the conclusions in the Judgment (re: the judicial review proceedings) that was handed down on 11 April 2022 about what is required to achieve compliance.
Implemented12 Apr 2022
CMP388Ofgem’s recent decisions on CUSC modifications CMP335/336 and CMP340/343 contained several small changes/clarifications that would be beneficial in addition to some identified by the ESO. This proposal seeks to implement these clarifications.
Implemented12 Apr 2022
CMP389Seeks to implement changes related to band boundaries as stated in paragraph 3.12 of Ofgem’s recent decision on CUSC modification CMP343.
Implemented12 Apr 2022
CMP390The National Security and Investment (NSI) Act 2021 enables Government to scrutinise the acquisition of rights in entities and assets and intervene where there is a risk to national security. This modification seeks to amend the CUSC application forms to recognise and provide consent to ESO sharing information about the applicant with Government enabling BEIS to carry out any initial national security checks in line with the NSI Act and identify any issues at an early opportunity
StandardWithdrawn10 Mar 2022
CMP385Improvements to Securities and Liabilities provisions within CUSC
also affects STC
Withdrawn9 Mar 2022
CMP386Proposes to introduce a new generation classification for battery storage and pumped storage which, in the view of the Proposer, reflects the value that storage assets in generation constrained areas provide to transmission licensees
Withdrawn9 Mar 2022
CMP387Seeks to create a new generation classification for storage, and to exempt storage operators contracted to provide stability services from Transmission Network Use of System (TNUoS) charges
Implemented8 Feb 2022
CMP384Applies adjustments for inflation to manifest error thresholds using Indexation
Implemented7 Feb 2022
CMP383To enable the ESO to recover the costs deferred under CMP381, a licence change is required. This will not be in place for 1 April 2022. Therefore CMP383 seeks to change the recovery of CMP381 costs, to when the new licence comes into effect until 31 March 2023.
Implemented11 Jan 2022
CMP382Seeks to ensure that the use of “charging year” and “Working Day” in Section 14 is replaced and aligned with the already defined “Financial Year” and “Business Day”.
Implemented16 Dec 2021
CMP381Seeks to set a £/MWh cap on BSUoS from 1 January 2022 until 31 March 2022, due, in the view of the Proposer, to exceptional market conditions making BSUoS much higher than industry parties could reasonably have expected. The additional BSUoS costs above the cap would be deferred to the 2022/23 charging year, using the same approach as CMP350 and the recovery mechanism approved under CMP373.
Implemented10 Nov 2021
CMP380Seeks to remove any gender specific references or terminology within the CUSC.
StandardImplemented9 Sept 2021
CMP379Determining TNUoS demand zones for transmission-connected demand at sites with multiple Distribution Network Operators (DNOs)
StandardImplemented15 Jul 2021
CMP376Inclusion of Queue Management process within the CUSC
also affects STC?
Implemented15 Jul 2021
CMP377Seeks to provide clarity on how the BSUoS charging methodology is described in Section 14 of the CUSC. The four areas being addressed are: Covid-19 cost recovery calculations, capitalisation of defined terms in CMP373 legal text, clarifying storage import terminology and general housekeeping
StandardDecision10 Jun 2021
CMP375Enduring Expansion Constant & Expansion Factor Review
Open pagealso affects STC
Implemented20 Apr 2021
CMP373On 9 April 2021, the ESO informed industry parties that they had underbilled BSUoS by ~£44m of Balancing Services costs incurred in 2020/21 made up of costs associated with trading activities and the Accelerated Loss of Mains Change Programme (ALoMCP). The Proposer is content with the approach for recovery of ALoMCP (~£10m) . However, the ESO have proposed to recover the cost associated with trading activities (~£34m) through the Reconciliation Final run (RF) for 2020/21, which the Proposer believes will cause significant problems for Suppliers, Generators and Consumers.
Implemented15 Apr 2021
CMP370A new Interactivity policy has been developed collaboratively with industry through the Energy Networks Association (ENA) Open Network Projects. This CUSC modification seeks to align the CUSC with this Interactivity policy.
Rejected15 Apr 2021
CMP371Allow Proposers to raise one CUSC Modification Proposal to seek changes to both charging and non-charging provisions within CUSC
Implemented15 Apr 2021
CMP378Seeks to place an obligation on The Company (defined in the CUSC as National Grid Electricity System Operator (NGESO) Limited) to comply with the obligations insofar as these apply to it under Section C12 (Market-wide Half-Hourly Settlement Implementation) of the Balancing and Settlement Code (BSC).
Rejected14 Apr 2021
CMP368 and CMP369CMP368 seeks to give effect to the Authority determination within the CMP317/327 decision published on the 17 December 2020 to amend the definition of Assets Required for Connection, create new definitions of ‘GB Generation Output’ and define Generator charges for use in the Limiting Regulation range calculation. To facilitate the change, CMP369 proposes to update the legal text relating to ‘Generation Output’ detailed in the tariff setting methodology within Section 14.14.5 and the Ex-Post Reconciliation within Section 14.17.37 of the CUSC to align with the updated definitions introduced by CMP368.
Implemented26 Mar 2021
CMP366Seeks to ensure that the legal text in paragraph 14.14.5 reads correctly, following the implementation of CMP346 and CMP324/CMP325 (WACM2).
Implemented26 Mar 2021
CMP367Seeks to amend Section 14 of the CUSC due to the overlap of the implementation of CMP333 and CMP360. It also aligns numbering within Section 14.30.
Implemented11 Feb 2021
CMP361To introduce an ex ante fixed volumetric BSUoS tariff set over a total fix and notice period of 14 months.
Implemented11 Feb 2021
CMP362To facilitate the implementation of BSUoS Reform by introducing and updating required definitions into CUSC section 11 from CMP308 and CMP361.
Implemented11 Feb 2021
CMP363CMP363 seeks to clarify the TNUoS Demand Residual charging arrangements for transmission connected sites that have a mix of Final and non-Final Demand.
Implemented11 Feb 2021
CMP364CMP363 seeks to clarify the TNUoS Demand Residual charging arrangements for transmission connected sites that have a mix of Final and non-Final Demand. CMP364 is to support CMP363 by changing Section 11 to add/amend/remove definitions as needed
Implemented11 Feb 2021
CMP365This modification is based upon the principles of Grid Code GC0131 ‘Quick Wins’. The aim is to incorporate a smoother and more efficient process for code modifications that will allow for the best use of industry time
Implemented11 Feb 2021
CMP372Seeks to ensure that retained EU law functions effectively in the context of the CUSC following the UK-EU Trade and Cooperation Agreement and the end of the transition period. It will ensure that the CUSC takes into account the provisions in the relevant Statutory Instruments prepared under the European Union (Withdrawal) Act 2018 as amended by the European Union (Withdrawal Agreement) Act 2020.
Implemented29 Jan 2021
CMP360To change the relevant parts of Section 14 so that the definitions and formulae used to calculate External and Internal BSUoS charges for each Settlement Period reflect the methodology used in the ESO Electricity System Operator licence for RIIO-2.
Withdrawn12 Jan 2021
CMP358The Small Generator Discount (SGD) is currently contained in the ESO’s licence. The SGD expires on 1 April 2021. Given the ongoing uncertainty over the Forward Looking and Access SCR, CMP358 proposes that the SGD is put into the CUSC and CMP359 will seek to define SGD and CPI/CPIH.
Withdrawn12 Jan 2021
CMP359The Small Generator Discount (SGD) is currently contained in the ESO’s licence. The SGD expires on 1 April 2021. Given the ongoing uncertainty over the Forward Looking and Access SCR, CMP358 proposes that the SGD is put into the CUSC and CMP359 will seek to define SGD and CPI/CPIH.
Implemented23 Dec 2020
CMP357To insert that the security factor for the purpose of calculating TNUoS tariffs will use the result of the assessment expressed to eight decimal places.
Implemented18 Dec 2020
CMP355Currently, Section 14 of CUSC uses the Retail Price Index (RPI) as the measure for index-linking various parts of the charging methodologies. With the RIIO2 Final Decision from Ofgem, the RPI measure of indexation has being replaced and so the CUSC needs to be revised accordingly to use the correct measure for setting TNUoS and Transmission Connection Asset (TCA) charges. CMP355 specifically seeks to change the relevant parts of Section 14 so that references to RPI are revised to the indexation method as set out in the transmission licence.
Implemented18 Dec 2020
CMP356Currently, Section 14 of CUSC uses the Retail Price Index (RPI) as the measure for index-linking various parts of the charging methodologies. With the RIIO2 Final Decision from Ofgem, the RPI measure of indexation has being replaced and so the CUSC needs to be revised accordingly to use the correct measure for setting TNUoS and Transmission Connection Asset (TCA) charges. CMP355 specifically seeks to change the relevant parts of Section 14 so that references to RPI are revised to the indexation method as set out in the transmission licence. CMP356 has been raised to support CMP355 by changing Section 11 to add supporting definitions
Implemented27 Nov 2020
CMP354Seeks to allow the ESO to ensure that any Capacity Allocation and Congestion Management Regulation (CACM) related payments (determined by the Authority) are paid to relevant interconnector licensees in 2021 and to facilitate the interconnector adjustment payment process for future Authority cost recovery decisions.
Implemented30 Oct 2020
CMP353Seeks to stabilise the locational signal at the start of the RIIO-2 period at the RIIO-1 value plus relevant inflation in each charging year until such time as the effect of any change in the locational signal can be better understood
Implemented15 Oct 2020
CMP352Amend the formulas in Appendix 2 of CUSC section 3 to ensure the 'Revised Indicative Annual TNUoS charge’ is calculated correctly
Implemented10 Sept 2020
CMP351To change the timescales by which Cash Deposits need to be provided to National Grid ESO through the bi-annual financial securities process.
Implemented30 Jul 2020
CMP349To clarify the definition of ‘Identified Onshore Circuit’ within Section 11 (Interpretations and Definitions) of the CUSC as a result of the CMP320 decision.
Implemented16 Jul 2020
CMP348To insert Exhibit Y (Electricity Balancing Guideline (EBGL) Mapping Table) into the CUSC and to amend the numbering in Section 6 (General Provisions).
Implemented15 Jul 2020
CMP350To change the BSUoS Covid Support Scheme introduced by CMP345 by 1) Reducing the current £15/MWh cap to £5/MWh; 2) Extending its application from 31 August 2020 to 30 September 2020; and 3) Introducing a formal limit of £100m for the amount to be deferred
Implemented26 Jun 2020
CMP346To amend incorrect and misleading references to old charging parameters in CUSC Section 14.
Implemented26 Jun 2020
CMP347To ensure the treatment for the three offshore local tariffs are consistent with each other and amend incorrect references relating to offshore local tariffs.
Implemented19 May 2020
CMP345Apply a cap of £15/MWh to the BSUoS price in each settlement period from the implementation date to the end of August 2020, Any under recovery of revenue from the application of the cap will be recovered through BSUoS charges equally across all settlement periods in the 2021/22 Charging Year.
StandardDecision13 May 2020
CMP344Clarification of Transmission Licensee revenue recovery and the treatment of revenue adjustments in the Charging Methodology
Open page
Implemented13 May 2020
CMP342Seeks to clarify, and confirm the position that NGESO has always applied, that when calculating the amount Users are required to secure under the CUSC, the amount of applicable Value Added Tax is to be included.
Implemented13 May 2020
CMP343Proposes the methodology for Transmission Demand Residual charges to be applied only to ‘Final Demand’ on a ‘Site’ basis, as well as how to treat negative locational charges and the application of any charging bands.
Withdrawn24 Apr 2020
CMP332To create a methodology by which the residual element of demand TNUoS can be apportioned to Half Hourly (HH) and Non Half-Hourly (NHH) demand, and a separate methodology to determine the ‘bands’ against which the residual element of demand TNUoS is levied
Implemented18 Mar 2020
CMP339Allow the CMP317/327 Workgroup to develop the appropriate definitions needed for the Original and any alternative Proposals and any other changes outside of Section 14 as appropriate.
StandardWorkgroup12 Mar 2020
CMP341CUSC Sandbox: enabling derogation from certain obligations to support small-scale trials of innovative propositions
Open pagealso affects Grid Code (GC0140)
Implemented12 Mar 2020
CMP340Seeks to allow the CMP343 Workgroup to develop the appropriate definitions needed for the Original and any alternative Proposals and any other changes outside of Section 14 as appropriate.
StandardImplemented16 Jan 2020
CMP337Impact of DNO Contributions on Actual Project Costs and Expansion Factors
StandardImplemented16 Jan 2020
CMP338Impact of DNO Contributions on Actual Project Costs and Expansion Factors – New Definition of Cost Adjustment
Implemented16 Jan 2020
CMP334CMP332 is developing a methodology for the Transmission Demand Residual to be applied only to ‘Final Demand’ on a ‘Site’ basis. This Modification creates the definitions of "Final Demand" and "Site".
Implemented16 Jan 2020
CMP335CMP332 is developing a methodology for the Transmission Demand Residual to be applied only to ‘Final Demand’ on a ‘Site’ basis. CMP334 creates the definitions of "Final Demand" and "Site". This modification aims to revise Section 3 and 11 of the CUSC to set out how/when the Residual is recovered from parties once the Residual charges are determined.
Implemented16 Jan 2020
CMP336CMP332 is developing a methodology for the Transmission Demand Residual to be applied only to ‘Final Demand’ on a ‘Site’ basis. CMP334 creates the definitions of "Final Demand" and "Site". This modification aims to revise Section 14 of the CUSC to set out how/when the Residual is recovered from parties once the Residual charges are determined.
Implemented20 Dec 2019
CMP333To give effect to Ofgem's decision to levy BSUoS to Suppliers on a gross volumetric basis.
StandardWorkgroup28 Nov 2019
CMP328Connections Triggering Distribution Impact Assessment
Open pagealso affects STC (CM078) DCUSA (DCP 392)
StandardDecision28 Nov 2019
CMP330/CMP374Allowing new Transmission Connected parties to build Connection Assets greater than 2km in length
Open pagealso affects STC (CM079) CUSC (CMP414)
StandardRejected28 Nov 2019
CMP331Option to replace generic Annual Load Factors (ALFs) with site specific ALFs
Implemented28 Nov 2019
CMP329Housekeeping Modification to amend National Grid Electricity Transmission Plc to National Grid Electricity System Operator in Schedule 2, Exhibit 7 of the CUSC
Implemented25 Oct 2019
CMP325The ESO has written a Cusc Modification Proposal (CMP324) to alter the manner in which rezoning is carried out within Section 14 of CUSC. This Mod proffers an alternative defect, better enabling the issue to be explored by a Workgroup
Implemented10 Oct 2019
CMP326To introduce a ‘Turbine Availability Factor’ into the CUSC to enable accurate calculation by the NGESO Control Centre and consequently accurate settlement of the Frequency Response capability of PPMs when some of the turbines on site are unavailable.
Implemented27 Sept 2019
CMP324The CUSC requires that generation zones, used for Transmission Network Use of System (TNUoS) tariff setting, are reviewed at the start of each price control period. This CMP seeks to change the zones and the underlying methodology used to establish them.
Implemented19 Sept 2019
CMP295Contractual Arrangements for Virtual Lead Parties (Project TERRE)
Implemented19 Sept 2019
CMP321Clarify the definition of ‘Affiliate’ within Section 11 of the CUSC as a result of CMP285 implementation.
Implemented19 Sept 2019
CMP322Seeks to amend the CUSC to create a mechanism for Ofgem to approve changes to the ESO Standard Contract Terms when those changes include amendments to the Terms & Conditions related to balancing.
Implemented19 Sept 2019
CMP323To ensure that the governance process for making future changes to the European Balancing Guidelines (EBGL) Article 18 (A18) T and Cs that are found in the CUSC incorporates the amendment process as laid out in EBGL Article 6 (A6) and Article (A10).
Implemented26 Jul 2019
CMP319As part of the Workgroup analysis, the Workgroup identified that CMP 280 and 281 are charging modification and as such can only change section 14 of the CUSC. If either modification is approved changes to other none charging sections of the CUSC will be required. These changes cannot be achieved with CMP280 And CMP281. The principle addition related to the definitions of storage as a class. The definitions are common to CMP 280, 281 and their alternates.
Implemented26 Jul 2019
CMP320Islands that have a MITS Node but are served by a single circuit radial link are exposed to non-cost reflective charging of a 1.8 Security Factor rather than the application of a 1.0 Security Factor. This proposal will apply a 1.0 Security Factor in that situation.
Implemented31 May 2019
CMP317/327Ensuring that average generator transmission charges set under the CUSC methodology did not fall below the €0-2.50/MWh range stipulated in EU regulation 838/2010 (The Limiting Regulation). (CMP317) Change the TNUoS Charging Methodology such that the Residual element of Generator TNUoS is £0 (CMP327)
Implemented22 May 2019
CMP318To extend the period over which Meter Point Administration Numbers (MPANs) in Measurement Classes F and G are treated as Non Half Hourly for Transmission Network Use of System (TNUoS) charging purposes
StandardDecision16 Apr 2019
CMP315TNUoS: Review of the expansion constant and the elements of the transmission system charged for
Open pagealso affects STC
StandardDecision16 Apr 2019
CMP316TNUoS Charging Methodology for Co-located Generation
Open page
Implemented21 Mar 2019
CMP313Critical Friend review period for submission of new modifications
Withdrawn15 Feb 2019
CMP309The proposed modification aims to ensure that retained EU law will function effectively in the context of the CUSC. In the event the United Kingdom leaves the European Union without an agreement, it will ensure that the CUSC takes into account the provisions in the relevant Statutory Instruments that have been prepared under the European Union (Withdrawal) Act 2018 as well as relevant consequential licence modifications.
Withdrawn15 Feb 2019
CMP310The proposed modification aims to ensure that retained EU law will function effectively in the context of the CUSC. In the event the United Kingdom leaves the European Union without an agreement, it will ensure that the CUSC takes into account the provisions in the relevant Statutory Instruments that have been prepared under the European Union (Withdrawal) Act 2018 as well as relevant consequential licence modifications.
Withdrawn15 Feb 2019
CMP311Seeks to change the amount of credit that is allowed to Suppliers under the User Allowed Credit requirements.
Implemented15 Feb 2019
CMP312Correcting erroneous legal text in Section 14 following implementation of CMPs 264/5 (consequential)
Implemented15 Feb 2019
CMP314To align the CUSC with the Grid Code on the use of Power Available in ESO headroom calculations for Power Park Modules.
Implemented19 Oct 2018
CMP308Seeks to better align GB market arrangements with those prevalent within other EU member states by removing BSUoS charges from Generation.
Implemented28 Sept 2018
CMP306Seeks to align the rate of return applied to the net asset value of connection points in the calculation of annual connection charges (as set out at paragraph 14.3.21 of the Connection Charging Methodology) to the pre-tax cost of capital in the price control of the Relevant Transmission Licensee (plus a margin of 1.5 percentage points in the case of MEA-linked assets). This will improve the cost reflectivity of the charges, since the return on capital will equal the Authority’s most recent assessment of that cost for the Relevant Transmission Licensee.
Withdrawn20 Sept 2018
CMP307Seeks to change the current collection of BSUoS from suppliers and embedded Exemptible generation to a methodology where BSUoS is charged on a gross basis to suppliers and BSUoS is charged on exports from embedded Exemptible generation.
StandardWorkgroup23 Aug 2018
CMP304Improving the Enhanced Reactive Power Service by making it fit for purpose
Open pagealso affects CUSC (CMP305)
StandardWorkgroup23 Aug 2018
CMP305Removal of the Enhanced Reactive Power Service (ERPS)
Open pagealso affects CUSC (CMP304)
Withdrawn23 Aug 2018
CMP302Extend the small generator discount until an enduring solution acknowledging the discrepancy between England and Wales, and Scotland is implemented
Rejected19 Jul 2018
CMP303Seeks to remove additional costs from local circuit expansion factors that are incurred beyond the connected, or to-be-connected, generation developers’ need.
Implemented21 Jun 2018
CMP301Building on CMP213, which introduced specific expansion factors for HVDC and subsea circuits, ensuring this is consistent with the rules for onshore circuits
Implemented17 May 2018
CMP300Seeks to improve the cost reflectivity of the Response Energy Payment (“REP”) for Balancing Mechanism Units (“BMUs”) with low or negative marginal costs, as a consequence of having a Contract for Difference (“CfD”)
Implemented27 Apr 2018
CMP299Consequential changes to the CUSC to facilitate the 2018-2021 ESO Incentive Scheme
StandardImplemented17 Apr 2018
CMP298Updating the Statement of Works process to facilitate aggregated assessment of relevant and collectively relevant embedded generation
also affects STC (CM080)
Implemented17 Apr 2018
CMP293Legal Separation changes to CUSC sections, Exhibits & Schedules (non charging)
Implemented17 Apr 2018
CMP294Legal Separation changes to CUSC Section 14
Implemented17 Apr 2018
CMP296Aligning the CUSC to the BSC post-P344 (Project TERRE) to exempt Virtual Lead Parties from BSUoS
Implemented17 Apr 2018
CMP297Aligning CUSC and BSC post-TERRE (Section 11) – consequential modification to introduce definition of Virtual Lead Party
StandardWorkgroup15 Feb 2018
CMP288Explicit charging arrangements for customer delays and backfeeds
Open page
StandardWithdrawn15 Feb 2018
CMP291The open, transparent, non discriminatory and timely publication of the harmonised rules for grid connection (in accordance with the RfG, DCC and HVDC) and the harmonised rules on system operation set out within the Bilateral Agreements
also affects Grid Code (GC0117) DCUSA
StandardImplemented15 Feb 2018
CMP292Introducing a Section 8 cut-off date for changes to the Charging Methodologies
Withdrawn15 Feb 2018
CMP289Consequential change to support the introduction of explicit charging arrangements for customer delays and backfeeds via CMP288
Implemented15 Feb 2018
CMP290Housekeeping change to CUSC Section 14 required as a result of the implementation of CMP264, CMP265, CMP268 and CMP282
StandardRejected10 Oct 2017
CMP286Improving TNUoS Predictability Through Increased Notice of the Target Revenue used in the TNUoS Tariff Setting Process
also affects CUSC (CMP244) STC
StandardWithdrawn10 Oct 2017
CMP287Improving TNUoS Predictability Through Increased Notice of Inputs Used in the TNUoS Tariff Setting Process.
also affects CUSC (CMP244) STC
Implemented20 Jul 2017
CMP285CUSC Governance Reform – Levelling the Playing Field
Withdrawn18 Jul 2017
CMP284Improving TNUoS cost reflectivity (Reference Node)
Implemented30 Jun 2017
CMP281Aims to remove liability from storage facilities for the Balancing Services Use of System (BSUoS) charges on imports.
Rejected22 Jun 2017
CMP280Seeks to remove the Transmission Demand Residual charge from generation and electricity storage
StandardWithdrawn2 Jun 2017
CMP276Socialising TO costs associated with ''green policies''
Rejected18 Jan 2017
CMP275Transmission Generator Benefits in the provision of ancillary and balancing services – levelling the playing field
StandardWithdrawn29 Sept 2016
CMP271Improving the cost reflectivity of demand transmission charges
Withdrawn29 Sept 2016
CMP274Proposed to update the transmission charging methodology to include a Peak demand tariff based on current locational element of the demand TNUoS charge methodology using the existing Triad methodology for determining user charges & a Winter Weekday demand tariff based on the current Demand residual element of the demand TNUoS charge methodology.
Rejected19 Aug 2015
CMP250Stabilising BSUoS with at least a twelve month notice period
Rejected19 Aug 2015
CMP251Removing the error margin in the cap on total TNUoS recovered by generation and introducing a new charging element to TNUoS to ensure compliance with European Commission Regulation 838/2010
TBCRejected
CMP459Charging TNUoS on a monthly basis
also affects TBC