Judicial appeal against electricity transmission remuneration: what changes for network operators

Key data

Electricity transmission companies and network operators face a scenario of regulatory uncertainty. CNMC Circular 7/2025, which amended the methodology for calculating electricity transmission remuneration by updating the unit reference values for investment and for operation and maintenance, has been challenged before the Audiencia Nacional through administrative appeal 4/331/2026.

The CNMC published the summons to interested parties on 23 March 2026 in the BOE (reference BOE-A-2026-6785). This opens a window for any company or agent with a legitimate interest to join the proceedings and defend their position before the court issues its ruling.

What does this regulation establish?

The resolution published by the CNMC does not directly modify any economic obligation: its function is to publicly notify that a judicial appeal is in progress and to give interested parties the opportunity to appear as a party in the proceedings.

To understand the substance of the dispute, it is necessary to understand what Circular 7/2025 changed:

The appeal challenges the legality of these changes. If the Audiencia Nacional upholds the appeal, Circular 7/2025 could be annulled in whole or in part, which would require recalculating the remuneration of network operators using the previous parameters or new ones set by the court.

Economic and operational impact

The outcome of the litigation has direct consequences for two critical variables for the sector:

• Revenues of transmission network operators: The remuneration recognised for transmission companies depends directly on the unit reference values set in the circular. A judicial annulment would imply reviewing revenues already recognised or those to be recognised during the processing of the appeal.
• Electricity tariffs: Transmission remuneration is a regulated component of the electricity tariff. Changes in the remuneration methodology may be passed on, to a greater or lesser extent, to the final cost of electricity for consumers and businesses.
• Regulatory stability: The challenge creates uncertainty about the effective validity of Circular 7/2025 while the appeal is being processed, which complicates financial planning for the affected operators.

While the appeal is pending resolution, Circular 7/2025 remains applicable, unless the court agrees interim suspension measures. Companies must operate under the current regulations, but must actively monitor the development of the proceedings.

Who is affected?

• Electricity transmission companies: These are directly affected by the challenged remuneration methodology. Their profit and loss account depends on the unit reference values set by the applicable regulations.
• Network operators: Any operator whose remuneration is calculated in accordance with Circular 7/2025 has a legitimate interest in the outcome of the appeal.
• Energy sector agents: Retailers, distributors and large industrial consumers may be indirectly affected if the outcome of the litigation impacts access tariffs to the transmission network.
• Legal and regulatory advisors in the electricity sector: They must inform their clients about the possibility of joining the proceedings and about the risks arising from regulatory uncertainty.

Practical example

An electricity transmission network operator whose annual remuneration has been recognised and calculated in accordance with the new unit reference values approved by Circular 7/2025 now faces the following situation:

• If it does not join the appeal and the court annuls the circular, the company will be bound by the ruling without having been able to defend its position or the remuneration values that are favourable to it.
• If it joins as an interested party, it can provide technical and economic arguments about the impact of the unit reference values on its activity, and defend the legality of the methodology approved by the CNMC.
• In the event that the appeal succeeds and the updated values are annulled, the company will need to recalculate its remuneration using the parameters of Circular 5/2019 or those established by a new circular, which could result in a reduction or modification of its regulated revenues.

The deadline to join the proceedings is determined by the summons resolution published on 23 March 2026. Acting swiftly is essential to avoid losing the procedural opportunity.

What should companies do now?

1. Assess legitimate interest: Determine whether the company has remuneration calculated in accordance with Circular 7/2025 or whether the outcome of the appeal may affect its regulated revenues or costs.
2. Consult with legal advisors specialised in energy law: Analyse whether it is appropriate to join administrative appeal 4/331/2026 before the Audiencia Nacional and within what timeframe, in accordance with the summons resolution published on 23 March 2026.
3. Monitor the status of the judicial proceedings: Follow the progress of the appeal before the Audiencia Nacional to detect whether interim suspension measures regarding Circular 7/2025 are requested or agreed, which would immediately change the applicable regulations.
4. Review financial planning: Incorporate into financial models the scenario of a possible annulment of Circular 7/2025 and a return to the parameters of Circular 5/2019, in order to assess the potential impact on regulated revenues.
5. Maintain application of Circular 7/2025 while it remains in force: Absent a judicial suspension order, the circular remains mandatory. Do not anticipate regulatory changes that have not yet been agreed by the court.

Official source

View full regulation at official source

Disclaimer: This article is for informational purposes only and does not constitute legal advice. For specific decisions, please consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-6785