SHERIDAN, WYOMING - April 03, 2026 - Wholesale energy market participants operating across EU borders now face a materially different compliance environment: ACER's newly published Rules of Procedure for cross-border investigations establish the procedural framework under which the agency exercises its expanded investigatory mandate, granted by EU legislators in 2024 under the revised REMIT framework. The 43rd edition of the REMIT Quarterly sets out these rules in full and signals an accelerating enforcement posture across European energy markets.
Expanded mandate and procedural rules
The 2024 revision of REMIT transferred new investigatory powers to ACER, specifically authorising the agency to pursue cross-border cases involving market manipulation and abuse in wholesale energy markets. Previously, such investigations relied primarily on national regulators operating under their domestic frameworks, which created gaps in multi-jurisdictional cases. ACER's new Rules of Procedure close that gap by defining how the agency initiates, conducts, and concludes cross-border investigations - including procedural rights of parties, evidence-gathering steps, and coordination mechanisms with national energy regulatory authorities.
The procedural framework also clarifies how ACER will engage with the European Commission and national competent authorities during active investigations. This structural clarity is significant: market participants under scrutiny now have a defined procedural pathway, and national regulators must align their own processes with ACER's lead in cross-border matters. The rules form the operational backbone of the agency's new enforcement tier above the national level.
Active enforcement and market surveillance data
The 43rd edition reports 456 REMIT breach cases under active review at the end of Q4 2025, providing a concrete measure of enforcement pipeline volume. This figure covers cases at various stages across national regulators and ACER, reflecting the cumulative scope of market integrity oversight across the EU's wholesale energy sector.
The Quarterly also includes a case report on an attempt to manipulate the Spanish gas market, which was investigated and sanctioned by Spain's national energy regulator, the CNMC. The case illustrates the continued role of national authorities within the REMIT enforcement architecture, even as ACER assumes a broader cross-border coordination role. Market surveillance data for 2025 showed a year-on-year increase in trading volumes on Organised Market Places, driven by growth in natural gas forward markets - a trend that elevates the systemic importance of robust surveillance infrastructure.
Upcoming regulatory changes and data reporting obligations
ACER's preparatory work on data reporting under the revised REMIT is ongoing, pending finalisation of the revised REMIT Implementing Regulation. Until that regulation is finalised, exact data reporting obligations for market participants remain in flux, but the Quarterly signals that ACER is actively preparing implementation infrastructure. Market participants should treat this as a firm signal that updated reporting requirements are approaching.
ACER is also planning to launch a public consultation on a new guideline on REMIT transaction reporting. The consultation will reflect evolving obligations under the revised REMIT framework, with details on scope and timeline to follow. The agency's stakeholder engagement plan for 2026, also featured in this edition, outlines how industry participants can contribute to that process. Takeaways from November 2025 events - including Expert Group meetings on Wholesale Energy Market Data Reporting and the ACER-European Commission REMIT workshop - are summarised in the Quarterly and provide early indicators of regulatory direction.
Business impact
Compliance and regulatory affairs teams at energy trading firms, utilities, and gas market participants must now map their cross-border transaction activity against ACER's new Rules of Procedure. Firms active in multiple EU member states are directly within scope of the cross-border investigatory framework. Compliance officers should review their internal investigation-response protocols, documentation standards, and legal representation arrangements to align with ACER's procedural requirements before the first formal cross-border case is filed under the new rules.
Energy data and reporting managers face a near-term decision point: ACER's ongoing work on the revised REMIT Implementing Regulation means that current data reporting infrastructure may require reconfiguration. The forthcoming public consultation on REMIT transaction reporting gives market participants a structured window to influence the final reporting format and scope. Firms that engage early in the consultation process will be better positioned to shape obligations that affect their operational systems and reporting workflows well into 2026 and beyond. Operations directors at commodity trading platforms and organised market places should also monitor the year-on-year trading volume trends flagged in the Quarterly, as elevated volumes on gas forward markets increase the likelihood of surveillance scrutiny and strengthen the case for investing in pre-trade compliance controls.