New Transmission Tariffs, Methodology and Interconnection Contract Model in Mexico

On 18 June 2026, Mexico’s Ministry of Energy (Secretaría de Energía, or “SENER”) published the guidelines for the Voluntary Migration of Self-Supply and Cogeneration Permits (Acuerdo por el que se emiten los Lineamientos para la migración voluntaria y expedita de autoabastecimiento y cogeneración de energía eléctrica a las figuras previstas en la Ley del Sector Eléctrico”, the “Guidelines”). The Guidelines entered into force on the day of publication, and affect certain legacy projects in Mexico, as discussed below.

The Guidelines affect legacy projects under the LSPEE

The Guidelines implement laws that mandated SENER to regulate the procedure for expedited migration of self-supply and cogeneration permits (Sixth, Seventh, and Eighth Transitory Articles of the Ley del Sector Eléctrico (LSE), of 18 March 2025, and the Nineteenth Transitory Article of its Regulations (published on 3 October 2025).

The Guidelines apply to holders of self-supply (autoabastecimiento) and cogeneration permits granted under the now superseded Power Public Service Law (Ley del Servicio Público de Energía Eléctrica, LSPEE). They also affect members of self-supply societies, establishments linked to cogeneration permits, and end users whose load centres fall within those legacy permits.

However, the migration is voluntary and permit holders who choose not to migrate retain their legacy permits and contracts until natural expiry under the original terms (per the Fifth Transitory Article of the LSE). Projects that hold both a self-supply/cogeneration permit and an independent power producer (PIE) permit under the LSPEE are not covered by these Guidelines, they must follow the separate PIE migration guidelines published on 16 April 2026.

Migration schemes and timeline

The migration window spans 19 June 2026 to 6 October 2028. The registration of expressions of interest opened on 19 June 2026 and will close on 18 September 2026.

After migration, permit holders may operate under one of the following LSE schemes: (i) isolated self-consumption; (ii) interconnected self-consumption (with or without sale of surpluses); or (iii) generation for the Wholesale Electricity Market. End users may alternatively migrate to receive Qualified Supply or Basic Supply. The Guidelines establish six modalities of migration, ranging from the migration of a power plant alone, to joint migration of plant and load centres, to migration of end users as Qualified Users or to Basic Supply.

For power plants, the process involves nine sequential stages over a period of 28 months: (1) registration of expression of interest (by 18 September 2026); (2) submission of migration application (September-October 2026); (3) review and admission (October-December 2026); (4) CNE (National Energy Commission) resolution and permit grant by February 202); (5) measurement functionality review (running in parallel); (6) preliminary registration of physical assets; (7) compliance with operating tests and metering (by August 2028); (8) formalisation of new contracts and early termination of legacy contracts; and (9) “Enabled” status and commencement of MEM operations (6 October 2028). End-user-only migrations follow a shorter timeline, largely concluding by April 2027.

Key conditions for an LSE permit

The grant of a new LSE permit results in the irrevocable renunciation and termination of the legacy permit for an existing project. The completion of the LSE licencing procedure results in the early termination of the corresponding legacy contracts. In addition, permit holders with multiple permits for the same plant must migrate all capacity into a single generation LSE permit.

No additional interconnection studies or reinforcement works are required for projects under legacy interconnection contracts. The grid operator, CENACE, is not authorized to request additional technical or administrative measures from license holders beyond those in the Guidelines.

For operating plants, the new permit will run for the remainder of the legacy term plus up to 15 additional years (not exceeding 30 years total), subject to approval of a Modernisation Programme. No increase in installed capacity is permitted during migration. License holders are not required to build energy storage infrastructure.

All deadlines set out in the timeline set out in the Guidelines cannot be extended and any failure to meet these deadlines will be considered a withdrawal from the process by the applicant.

Points for attention

In light of the Guidelines, licence holders wishing to migrate to an LSE permit will want to:

• Act promptly, as the window to register an expression of interest closes on 18 September 2026.
• Assess commercial positions. Companies should review energy banking and compensation arrangements under existing interconnection contracts, financing agreements, and partner or member interests before committing. As migrations requires irrevocable renunciation of legacy rights and early termination of legacy contracts, as well as changes to transmission charges.
• Monitor developments regarding updates to the Wholesale Electricity Market Rules.