Newsflash - SENER amends the Migration Guidelines and the New Transmission Methodology

I. Amendment to the New Methodology

On September 30, 2026, the Ministry of Energy (Secretaría de Energía, “SENER”) published in the Official Gazette of the Federation (Diario Oficial de la Federación, “DOF”) the Resolution of the National Energy Commission amending the Resolution issuing the methodology for determining the charge corresponding to the electric power transmission service provided by the Supplier to Permit Holders with electric power generation plants that have entered into an interconnection agreement and an agreement for electric power transmission service under the Public Electricity Service Law, published on June 18, 2026 (Acuerdo de la Comisión Nacional de Energía por el que se modifica el diverso por el que se emite la metodología para la determinación del cargo correspondiente al servicio de transmisión de energía eléctrica que preste la Suministradora a las Personas Permisionarias con centrales de generación de energía eléctrica, que cuenten con contrato de interconexión y convenio para el servicio de transmisión de energía eléctrica celebrados al amparo de la Ley del Servicio Público de Energía Eléctrica, publicado el 18 de junio de 2026, the “Amendment to the New Methodology”).

The principal features of the New Methodology were described in our Newsflash dated June 23, 2026, which may be consulted at the following link: https://www.ritch.com.mx/prensa/newsflash-sener-y-cne-lanzan-nuevas-reglas-para-proyectos-lspee

The Amendment to the New Methodology provides, among other matters, for the following:

a. Temporary exception to the application of the New Methodology

The New Methodology does not apply, during the period from October 19, 2026, to October 6, 2028, to Permit Holders with electric power generation plants that meet the following conditions:

(i) They have an Interconnection Agreement and a Transmission Agreement in force, entered under the Public Electricity Service Law (Ley del Servicio Público de Energía Eléctrica, “LSPEE”); and

(ii) They commence the voluntary and expedited Migration Procedure to the schemes set forth in the Electricity Sector Law (Ley del Sector Eléctrico, “LSE”) by registering the notice of interest and filing the corresponding migration application, in accordance with the Guidelines.

It should be noted that the temporary exception to the application of the New Methodology will take effect as from the day following the date on which the conditions set forth in paragraphs (i) and (ii) above are satisfied, and may not commence prior to October 19, 2026, nor have retroactive effects (the “Exception Period”).

During the Exception Period, Permit Holders must continue to operate under their existing Interconnection Agreement and Transmission Agreement and must pay the Charge corresponding to the Transmission Service in accordance with those instruments and the applicable transmission methodology.

The temporary exception to the application of the New Methodology will remain in effect only for so long as the above conditions continue to be met, and will end on October 6, 2028, except as provided below.

b. Grounds for termination of the exception

The temporary exception to the application of the New Methodology will cease to be effective where Permit Holders fall within any of the following scenarios:

(i) Failing to complete all stages of the Migration Procedure to the schemes set forth in the LSE established in the Guidelines;

(ii) The status of the physical assets registry is modified to “Enabled” and operations commence in the Wholesale Electricity Market (Mercado Eléctrico Mayorista, “MEM”), in accordance with the Migration Procedure;

(iii) The term of the Interconnection Agreement and the Transmission Agreement entered into under the LSPEE expires; or

(iv) They voluntarily waive the temporary exception to the application of the New Methodology before the National Energy Commission (Comisión Nacional de Energía, “CNE”), at any time.

In any of the above scenarios, once the CNE notifies Permit Holders of the relevant acts, they must pay the Charge corresponding to the Transmission Service, or the applicable MEM tariffs, as from the billing period immediately following the date of such notice.

II. Amendment to the Guidelines

It should be noted that, the Guidelines for voluntary and expedited migration from self-supply and cogeneration of electric energy to the legal frameworks set forth in the LSE (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”), were amended by the SENER on September 8, 2026 (the “Amendment to the Guidelines”).

The Amendment to the Guidelines provides for the following principal clarifications:

a. New timelines

(i) Expression of interest – June 19 to December 18, 2026.

(ii) Migration application – September 21, 2026, to January 15, 2027.

(iii) Completion date for the Joint Migration Procedure – October 6, 2028.

(iv) Deadline to obtain “Enabled” status for Load Centers that chose the Independent Migration Procedure – July 23, 2027.

b. Power Plants in operation

In the case of Power Plants in operation, the term of the generation permit granted, if any, may be extended for up to 15 (fifteen) additional years, without exceeding 30 (thirty) years in total, for which purpose the Applicant must submit, for the CNE’s assessment, the Modernization Program evidencing the reliable, efficient and safe operation of the Power Plant during its term and, where applicable, the modernization, testing or rehabilitation actions carried out.

c. Electric Energy Storage System

Where the Applicant intends to integrate an Electric Energy Storage System in its migration application, it must: (a) file the corresponding studies together with such application; or (b) if it has already requested them, report and evidence that circumstance in the migration application itself, so that the National Energy Control Center (Centro Nacional de Control de Energía, “CENACE”) gives them priority attention and issues the corresponding document prior to the granting of the permit under the applicable scheme set forth in the LSE.

d. Early compliance

If the Applicant intends to bring forward: (i) the Minimum Operating Tests; (ii) compliance with Metering System requirements; or (iii) compliance with the requirements to obtain “Dispatchable” status, it must propose in its migration application the commencement date for each of those activities.

CENACE must rule on the feasibility of such proposal in the Third Stage of the Migration Procedure.

e. Market Participant

If, as of the date on which the migration application is filed, the Applicant has not executed the contractual instrument with the Market Participant that will represent it in the MEM, it will be sufficient for it to identify such Market Participant in the migration application and to submit a letter of intent executed by both parties.

Notwithstanding the foregoing, the contractual instrument must be executed prior to May 16, 2027, or July 4, 2027, as applicable.

f. Basic Supply

Load Centers that decide not to migrate, or that fail to complete the Migration Procedure, will continue to receive Basic Supply under their existing agreement.

Likewise, local loads that, as a result of the Migration Procedure, form part of an electric power generation permit may continue to receive Basic Supply under their existing agreement.

g. Metering Systems

Where the components of the Metering System comply with the requirements set forth in the Market Rules, Applicants may continue to use them during the Migration Procedure and once it has been completed, without the need for any additional filing. Likewise, where applicable, the necessary adjustments may be made to such components so that they comply with the Market Rules and may continue to be used.

Please feel free to contact your usual Ritch Mueller contacts to discuss any questions related to the matters described in this note. For this purpose, we have made available our email address, through which we may route your inquiry to the appropriate members of our team.