Today, ACER publishes the first set of its revised REMIT data reporting documents, providing policy and technical instructions on how to report wholesale energy market data to ACER.

REMIT is the EU-wide framework that detects and deters market manipulation and abuse in wholesale energy markets, enhancing transparency and trust in the integrity of Europe’s energy markets.

What’s changing?

Following the revision of REMIT (2024) and of its secondary legislation (2026), new data reporting requirements will be introduced in three phases between October 2027 and July 2028. To help market participants and other reporting parties meet their new obligations, ACER is updating its guidance in three sets, one per phase. 

This first set covers exposure and continuous reporting, LNG market data and bilateral transactions with energy intensive consumers. The corresponding first-phase requirements will apply from 29 October 2027. Until then, reporting continues as under the current framework and existing guidance.

What’s in this first set of guidance? 

• Transaction Reporting User Manual (TRUM), providing updated technical instructions on how to report wholesale energy products under REMIT.

• Q&As on transaction reporting (formerly FAQs), answering stakeholders’ most relevant questions.

• Guideline on transaction reporting, bringing together existing policy guidance and clarifying who must report, what and when, including an annex on derivatives reporting. The document is published alongside the evaluation reports of the recent public consultations on the guideline and its annex.

• New Guidance on exposure reporting with practical examples to clarify reporting requirements and their application for this new data.

• Updated and new electronic formats for collecting transaction data.

Together, these documents give reporting parties a clear, practical basis to prepare for the new requirements and report consistently across the EU. They were developed in consultation with stakeholders, national regulatory authorities (NRAs) and the European Commission.

What’s next? 

• 23 November 2026: ACER webinar on the first set of guidance (Register for free).

• 27 November 2026: Publication of the new guidance for reporting parties under REMIT Delegated Regulation. 

• Early 2027: Revision of the ACER Guidance and Q&As on REMIT to align them with the recast Implementing Regulation on data reporting.

• Ahead of each next phase (May and November 2027): Public webinar after each set of revised guidance. 

Any questions?

ACER is collecting questions ahead of its webinar (23 November). Submit your questions by Monday 16 November 2026.

For technical queries or specific reporting situations, contact us at REMIT Query Form, as these will not be covered during the webinar.

In summer 2026, disruptions to liquefied natural gas (LNG) flows linked to the conflict in the Middle East, low gas storage levels after winter 2025-2026 and slower refilling contributed to tighter supply and pushed the EU’s gas prices higher.

ACER’s latest gas Monitoring Report looks at developments during the 2026 gas summer season and what they could mean for security of supply in winter 2026-2027.

What trends did ACER’s monitoring find?

• EU gas stocks remain below historical levels after a slow summer refill. At the end of winter 2025-2026 underground gas storage levels reached 28% of capacity, down from 34% a year earlier. By 21 October 2026, EU storage stood at 75%.

• Refilling storage has become more expensive. The upper bound estimated cost of refilling storage in 2026 reached €27 billion, while the average cost of injected gas was the second highest in the past decade. The conflict in the Middle East contributed to higher gas prices.

• EU reliance on US LNG continued to grow, as Qatari and Russian supplies fell. US LNG now accounts for around 30% of total EU gas supply, and total Russian gas around 11%. Russian LNG imports are 2% lower than in summer 2025, while Russian pipeline imports fell by 3%. The total EU LNG imports fell by 14%. No significant volumes of Qatari LNG reached the EU in summer 2026. 

• Gas prices rose as Europe competed for LNG in a tighter global market. Spot EU hub prices closed to near EUR 90/MWh mid-October 2026.

• The Middle East conflict added an estimated €18-33 billion to Europe’s gas import bill for the same quantity of gas. These additional costs are spread across the gas value chain, affecting household and industrial consumers and driving up electricity prices. Disrupted Qatari exports through the Strait of Hormuz increased EU reliance on other suppliers, especially the USA.

• Hot weather and droughts during summer increased demand for gas-fired power generation. Gas generation rose by nearly 9% over the gas summer period and by 20% in August compared to the same period in 2025.

Looking ahead

• A tighter winter supply balance: The EU will enter the winter with lower overall storage levels than the nine-year average. Gas demand is around 20% lower since the 2022 gas crisis, increasing the relative value of current storage levels. Weather-driven demand will be impacting the gas storage stocks' evolution.

• The EU is expected to continue to face international competition for securing LNG imports: The EU and Asia will continue to compete for flexible spot LNG cargoes during the heating season, possibly increasing exposure to price pressure and volatility. 

• The EU's winter prospects may lead to higher LNG needs: The actual level of LNG imports needed will ultimately depend on, inter alia, the severity of the winter weather and gas demand. In the current context, additional LNG imports are mainly to come from the USA in view of reduced Qatari supply and the Russian LNG phase-out from January 2027.

On 5 November 2026, ACER will open a public consultation on the preliminary version of EU-Flex, an open-source electricity market model developed to assess flexibility needs across the EU.

Electricity flexibility is the power system’s ability to respond to changes in supply and demand. Under the EU’s Electricity Market Design reform (2024), ACER is tasked with estimating flexibility needs across the EU and identifying potential gaps.

The first assessment is planned for July 2027, with the EU-Flex model supporting this process.

Why consult?

Stakeholders will have the opportunity to explore the proposed modelling approach ahead of the 2027 assessment.

The preliminary release of EU-Flex will include:

• An explanatory paper introducing the model and demonstrating its use through a test case.

• The preliminary model, including its source code and test case input data.

• A document describing the underlying methodology.

The consultation will help ACER gather feedback on the model and its methodology, as well as identify potential gaps, limitations and areas for improvement.

Get involved!

The public consultation will run from 5 November to 17 December 2026.

On 17 November 2026, ACER will hold a webinar to present the model, explain its key features and demonstrate how to run it. Register for free.