ACER has published its Recommendation to the European Commission on measures to speed up the effective implementation of EU electricity market rules. 

ACER’s monitoring found that major delays in implementing these rules hinder the proper functioning of Europe’s electricity system, resulting in economic costs for market participants and consumers.

Background

The EU electricity market is grounded in a comprehensive legal and regulatory framework. This includes EU-wide network codes and guidelines and the adoption of detailed rules (e.g. terms and conditions or methodologies (TCMs)), designed to ensure that the market operates efficiently. 

These rules set out key responsibilities for transmission system operators (TSOs), nominated electricity market operators (NEMOs), the European Network of Transmission System Operators for Electricity (ENTSO-E) and regional coordination centres (RCCs). 

Why an ACER Recommendation to the European Commission?

ACER’s (2024) monitoring found major delays in implementing the TCMs both at EU and regional level, affecting key areas such as electricity balancing, system operation and forward capacity. Delays in some TCMs had a domino effect, as they stalled progress of other TCMs.

This ACER Recommendation responds to the European Commission’s (2024) request for advice on how to strengthen the regulatory framework to reduce delays, with a focus on enforcement, governance and incentives.

What are ACER’s findings and recommendations? 

ACER’s Recommendation identifies challenges in three main areas:

• Implementation timelines: deadlines are often unclear or lack sufficient justification, making it difficult to track progress.
• Non-compliance: the decision-making process for addressing non-compliance by ENTSO-E and RCCs has room for improvement.
• Collective non-compliance: while the enforcement of individual obligations of TSOs and NEMOs poses no problem, current enforcement processes could fall short when tackling delayed implementation or failure to comply in cases where, across Union obligations, all TSOs or all NEMOs are tasked with jointly carrying out an obligation and collectively fail.

ACER recommends that the European Commission strengthen the regulatory framework by:

• Improving implementation and monitoring, introducing clearer deadlines and reporting requirements to reduce delays.
• Strengthening the enforcement framework in the ACER Regulation to ensure non-compliance by ENTSO-E and RCCs is addressed consistently and effectively.
• Assessing how to further improve enforcement for collective obligations (i.e. all TSOs and all NEMOs obligations).

On 20 April 2026, ACER will open a public consultation on amendments to the gas network code on interoperability and data exchange. The aim is to assess the need to amend the network code to reflect recent regulatory and market developments.

Why is this relevant?

The Interoperability and Data Exchange Network Code establishes the framework for operating the EU gas network and exchanging information between network users. Since its adoption in 2015, European gas markets have changed, driven by:

• an evolving regulatory framework (2024 Gas and Hydrogen Regulation);
• the EU’s decarbonisation ambitions; and
• the introduction of a new European standard on gas quality (CEN EN 16726).   

The European Commission invited ACER to assess whether the network code remains fit for purpose in light of these developments or if amendments are needed.

This consultation will support ACER in its assessment, ensuring that any amendment proposals are practical and aligned with market needs.

Have your say!

The public consultation will run from 20 April to 20 May 2026.

ACER will analyse the feedback received and evaluate the next steps for the network code review.

ACER has updated Annex VII of its Manual of Procedures and related FAQs on how to report ‘inside information’ under REMIT. The aim is to further harmonise the disclosure of inside information by providing additional guidance and improve overall data quality of inside information.

What is ‘inside information’ and why does it matter?

The Regulation on Wholesale Energy Market Integrity and Transparency (REMIT) is the EU-wide framework that aims to prevent wholesale energy market abuse and support fair competition.

Under REMIT, information is considered ‘inside information’ if it is:

• precise in nature;
• not yet public;
• directly or indirectly related to wholesale energy products; and
• likely to significantly affect wholesale energy prices if made public.

REMIT requires companies to disclose inside information (such as planned power outages for maintenance, or disruptions to transmission or gas storage), so that all players have the same information at the same time. This helps energy market transparency and integrity.

ACER’s REMIT Manual of Procedures provides guidance on how to report data, including inside information.

What’s new in the Manual?

The update focuses on Annex VII of the Manual (concerning inside information) and introduces clarifications and improvements, including:

• clearer terminology;
• updates to urgent market messages (related to the public disclosure and reporting of inside information);
• guidance on the disclosure of overlapping unavailability events; and
• revised definition of the affected asset code. 

Five of the six updates clarify existing guidance, while the remaining one introduces a change to enhance data quality and surveillance activities. Key improvements include: 

• Message ID (data field 1): Clarification of key terms such as “urgent market messages” (UMMs), "UMM Thread ID" and "version number", to help users better identify and track messages.
• Event status (data field 2): Clearer guidance on how to report the status of an event (e.g. whether an outage is ongoing or resolved), including the principle that published information should remain unchanged and updates should be published as a new version.
• Type of information (data field 3): Clarification on how to classify unavailability events (such as outages or maintenance), while remaining consistent with the Gas Transparency Regulation (EU) 2024/1789.
• Unavailable and available capacity (data fields 9 & 10): Improved guidance on reporting overlapping events, by extending the FAQ 5.1.9 in the Manual and including an example to provide clarification.  
• Affected asset or unit EIC code (data field 17): This field becomes mandatory (both at guidance and schema level), meaning market participants must always identify which asset is affected by the event. Additionally, EIC codes for substations can be reported.

This update is based on the reporting requirements under the current Implementing Regulation (2014) and represents a step towards the development of future inside information reporting under the revised REMIT Regulation (2024). 

Next steps

Market participants have nine months to implement these changes and comply with the new version of the guidance (i.e. by December 2026).

See all updated documents on ACER REMIT Portal.

Coming soon

• ACER public consultation on a new guideline on REMIT transaction reporting. 
• ACER and European Commission webinar: New rules for energy market integrity and transparency (23 April 2026).
• ACER and European Commission annual REMIT workshop (11 June 2026).

Today, ACER publishes its Recommendation on how national regulatory authorities (NRAs) should report barriers to non-fossil flexibility. The document provides clear guidance and indicators to ensure consistent reporting across Member States and help NRAs and relevant entities evaluate these barriers as part of their flexibility needs assessments.

What is non-fossil flexibility? 

Non-fossil flexibility is the energy system’s ability to quickly adapt to changes in electricity supply and demand, without relying on fossil fuels or costly grid expansions. It does so by shifting electricity consumption or generation to times or locations where the system is less constrained.

Unlocking flexibility helps foster a more efficient electricity system, supports the integration of renewables and contributes to lowering consumer bills. 

Why an ACER Recommendation?

The EU Electricity Regulation requires Member States to carry out flexibility needs assessments to determine how much clean flexibility their electricity systems require, including identifying existing barriers. These national assessments are harmonised across the EU through a common methodology approved by ACER in July 2025. 

This ACER Recommendation complements this process, by: 

• Setting out clear guidance on which barriers, indicators and evaluation methods Member States may consider when preparing their assessments.
• Streamlining the assessment process, consolidating ACER’s prior work on barriers (2023 and 2025) across all types of non-fossil flexibility and incorporating stakeholder input (winter 2023-2024).
• Ensuring comparable reporting across countries, supporting ACER’s forthcoming EU-wide analysis of barriers to clean flexibility identified in national assessments.

What does ACER recommend? 

ACER recommends that NRAs, in coordination with relevant entities, consider the main barriers to non-fossil flexibility when drafting their national reports. These include:

• Lack of proper legal framework for households, new entrants or aggregators to participate in electricity markets and system operation services.
• Lack of enablers and incentives for flexibility, such as smart meters and flexible retail contracts that help consumers shift their consumption.
• Restrictive rules to provide balancing and congestion management services.
• Complex, lengthy and discriminatory administrative requirements, including inefficient grid connection processes.
• Limited regulatory incentives for system operators to invest in non-wire, innovative grid technologies. 

What are the next steps? 

Member States are expected to complete their flexibility needs assessments by July 2026. ACER will then have a year to analyse the findings and publish an EU-wide analysis to:

• estimate flexibility needs across the EU;
• evaluate existing barriers to clean flexibility, including those identified in national assessments; and
• provide recommendations on issues of cross-border relevance (including measures to remove barriers to non-fossil flexibility).