Legal challenge against electric transport remuneration: what it means for the sector

Key data

Electric transport network operators and energy sector agents face a scenario of regulatory uncertainty. An administrative litigation case filed before the National Court, identified as 4/331/2026, challenges the Circular 7/2025, of 16 December, from the National Commission of Markets and Competition (CNMC). This circular modified the methodology for calculating electric transport remuneration, updating the unit reference values for investment and operation and maintenance of facilities.

The CNMC has published the summons to interested parties through a Resolution of 12 March 2026, giving those with legitimate interest the opportunity to intervene in the judicial proceedings before it advances without their participation.

What does this regulation establish?

The resolution published on 23 March 2026 in the BOE (reference BOE-A-2026-6785) is a formal summons: the CNMC publicly notifies that there is an ongoing judicial challenge and that any company or agent with legitimate interest can join the proceedings as a party.

The subject of the challenge is Circular 7/2025, which modified Circular 5/2019, of 5 December, the regulation that establishes the methodology for calculating remuneration for electric energy transport activity. Circular 7/2025 specifically updated:

• The unit reference values for investment per fixed asset element.
• The unit reference values for operation and maintenance per fixed asset element.
• The standard installations used in the remuneration calculation.

These values form the basis on which the income each transport company receives for its regulated activity is calculated. Any modification to them has direct impact on recognized revenues.

Economic and operational impact

The outcome of the litigation could have relevant economic consequences for the sector:

• If the challenge succeeds: the remuneration methodology approved by Circular 7/2025 could be annulled in whole or in part. This would imply reviewing the revenues recognized to transport network operators, with possible retroactive effect or future adjustment of remuneration.
• If the challenge is dismissed: Circular 7/2025 is confirmed and the new unit reference values are consolidated as the remuneration basis.
• Impact on electricity tariffs: transport remuneration is a regulated component of the electricity tariff. Changes in this remuneration can ultimately be passed on to the tolls paid by consumers and companies.
• Risk of regulatory instability: the mere existence of the challenge creates uncertainty about the validity of the approved values, which can affect the financial planning of operators.

Who does it affect?

• Electric energy transport companies whose remuneration is calculated using the challenged methodology.
• Transport network operators that have recognized regulated revenues based on the unit values of Circular 7/2025.
• Energy sector agents with interest in regulatory stability of electric transport: distributors, retailers, large industrial consumers.
• Legal and regulatory advisors who manage their clients' position before the CNMC and the National Court.
• CFOs and financial directors of energy companies who must provision for possible remuneration adjustments in their accounts.

Practical example

A company owning electric transport facilities receives annual remuneration calculated on the unit reference values for investment and operation and maintenance approved by Circular 7/2025. If the National Court were to uphold challenge 4/331/2026 and partially annul that circular, the values applied could revert to those established in Circular 5/2019 or be recalculated according to a new methodology ordered by the court. This could result in different remuneration—higher or lower, depending on the direction of the challenge—for each fixed asset element of the transport network.

Additionally, if this company does not intervene in the proceedings and the ruling is unfavorable to it, it will have lost the opportunity to defend its position as a party to the litigation. The summons published by the CNMC is precisely the mechanism to avoid this scenario.

What should companies do now?

1. Assess whether they have legitimate interest in the outcome of challenge 4/331/2026: if your company's remuneration is calculated using the methodology of Circular 7/2025, you have direct interest in the litigation.
2. Consult with legal advisors specialized in energy regulation to assess whether it is advisable to intervene in the proceedings before the National Court and in what capacity (as a supporting party or with another procedural position).
3. Review potential financial impact: analyze what variation in remuneration would result from a total or partial annulment of Circular 7/2025, and whether it is appropriate to establish any accounting provision.
4. Monitor the progress of the judicial proceedings: the procedural deadlines before the National Court are relevant; once the intervention period closes, it will not be possible to join the litigation.
5. Inform governing bodies (board of directors, management committee) about the regulatory risk represented by this challenge and its possible effects on regulated revenues.