The Netherlands Authority for Consumers and Markets (ACM) has announced adjustments to the accounting rules (RAR) that heat suppliers must follow. This decision comes after an investigation into the financial returns of five heat suppliers revealed that they were calculating their returns in inconsistent ways, complicating ACM's regulatory efforts.

Households connected to heat networks benefit from protections under the Dutch Heat Act, which mandates maximum rates to ensure that consumers do not pay more than those using traditional gas boilers. To monitor compliance with these maximum rates, ACM requests annual financial return reports from heat suppliers, publishing the findings in its Financial-return Monitor. Since 2023, ACM has also had the authority to investigate individual heat suppliers.

In its recent investigation, ACM focused on the financial returns of heat delivery to households, noting that returns for large-scale users are not regulated. The five suppliers under scrutiny cooperated fully, granting access to their administrative systems. Following the investigation, four suppliers submitted revised financial data, indicating that they had previously reported incorrect figures. ACM has warned that enforcement actions will be taken against any suppliers that submit inaccurate data in the future.

Despite the discrepancies, ACM's investigation did not find evidence of unreasonable returns among the suppliers. However, the flexibility in how suppliers allocate their financial returns—based on factors like the number of connections or the volume of heat supplied—has led to varied reporting practices. This variability has made it challenging for ACM to assess the appropriateness of the suppliers' cost allocation methods.

To address these issues, ACM has tightened the accounting rules, limiting the options available to suppliers for reporting their financial returns. This change aims to create a more uniform and transparent picture of the returns for the upcoming 2024 Financial-return Monitor. ACM plans to conduct another investigation into the financial returns of heat suppliers later this year.