Regulatory developments

The most important development in the area of economic regulation in 2025 concerns the preparation of new method decisions for the period 2027 to 2031. In addition, significant steps have been taken in the development of a new tariff system for customers in the small consumer segment.

Tariffs for transmission and connection

In accordance with the regulation system, the 2025 tariffs for the transmission and connection service, and therefore the revenue for 2025, take into account the tariffs for the procurement of national transmission and the costs of network losses to be compensated in 2025. The higher, newly established permitted income from normal operations for 2025 is also in line with the ACM's amended decisions for the period 2022 - 2026, and in accordance with that same amended decision, most of the credit for the years 2022 to 2024 has been incorporated into the tariffs for 2024 and 2025. The remaining portion has been incorporated into the 2026 tariffs. Finally, a correction to the compensation for the costs of network losses in 2023 has also been implemented for both electricity and gas, because the actual costs of network losses in 2023 were lower than the allocated income for the year 2023.

This results in an average increase of 9% in 2025 for these tariffs for electricity and an average decrease of 4% for gas.

In November 2025, the ACM made the regular tariff decisions for the year 2026. In the context of those decisions, the final portion of the credit for electricity for the years 2022 to 2024 has been incorporated into the tariffs. This in itself does not lead to a tariff change, as 50% had already been incorporated into the 2025 tariffs. On balance, the tariffs for the electricity transmission and connection services will increase by an average of 3%, in line with inflation. The average increase in the tariffs for the gas transport and connection service is 13%. This increase compared to the 2025 tariff level is primarily due to the fact that the 2025 tariffs included a large one-off downward adjustment for the costs of network losses from 2023. This is not the case in the 2026 tariffs, as the (lower) estimate for the costs of network losses is more in line with the actual costs for network losses in 2024. Secondly, there was an increase in the compensation amounts, because ACM concluded that the network operators are entitled to additional compensation to cover costs that do not decrease when customers purchase less transmission capacity. These include depreciation costs of existing networks.

Change to cost-plus regulation from 2027 onwards

Last year, ACM conducted an extensive consultation on the regulatory method to be used from 2027 onwards, which resulted in a draft method decision in September 2025.

The main conclusion here is that, as expected, ACM is changing its method from benchmark regulation to a form of individual cost-plus regulation. This means, for example, creating favourable conditions for the immense investment task in the area of electricity, as well as responding appropriately to declining gas consumption. This is in line with Liander's interests in carrying out its operations to efficiently implement the activities required for the energy transition, while also giving due consideration to investment security.

Under this new regulatory methodology, the future efficient cost levels are no longer estimated for all regional network operators for a period of five years based on historical data prior to the regulatory period. Instead, the aim is to ultimately reimburse the actual efficient costs per network operator. This is based on the network operator’s estimate of the cost level, investment scope and sales volumes, and ACM will supervise the development of costs by monitoring costs and assessing processes and other aspects at the network operators.