The Registro Nacional de Emisiones is SEMARNAT's database of greenhouse gas and compound emissions from the establishments required to report. Article 87 of the General Climate Change Law creates it, and a Regulation published in the Diario Oficial de la Federación on October 28, 2014 governs it.

Establishments in the energy, industry, transport, agriculture, waste, and commerce and services sectors whose direct and indirect emissions add up to 25,000 tonnes of CO2 equivalent or more a year. In energy and industry the threshold is measured per facility; in the other four sectors, by adding up every facility of the company.

Between March 1 and June 30 each year, with the emissions from January 1 to December 31 of the previous year. It is filed in the greenhouse gas section of the Cédula de Operación Anual, the COA, through the COA Web platform.

Which grid emission factor applies?

The one SEMARNAT publishes each year in a notice. For the 2024 report it was 0.444 tCO2e per MWh. For the 2026 COA, SEMARNAT asked filers to use that same factor because the 2025 one was not yet published.

How often is it verified?

Every three years. The opinion is issued by a body accredited and approved by SEMARNAT and filed between July 1 and November 30 of the year the verification is due.

What happens if I do not report, or report wrongly?

Article 115 of the General Climate Change Law sets fines of 3,000 to 10,000 days of minimum wage for filing false information or missing the deadline. PROFEPA can inspect and request the supporting records, which must be handed over within 15 working days.

RENE and COA: who reports emissions in Mexico

On May 29, 2026 SEMARNAT published a one-page notice: because the 2025 grid emission factor was not ready, that year's COA was to be calculated with the 2024 one, 0.444 tonnes of CO2 equivalent per megawatt hour. The window closed on June 30.

That is how concrete the RENE is. One threshold, one window a year, one factor that changes and one verification every three years. This guide walks through all four with the text of the Regulation and the notices in force.

RENE and COA are two different things

The Registro Nacional de Emisiones, RENE, is the database. Article 87 of the General Climate Change Law creates it, and its own Regulation, published in the Diario Oficial de la Federación on October 28, 2014, governs it.

The Cédula de Operación Anual, COA, is the form you report with. It is the same filing many plants already use to declare air emissions, discharges and hazardous waste to the RETC. The COA has a greenhouse gas section, and that section is what feeds the registry.

If your establishment only has to report greenhouse gases, you fill in that section alone. If you already had other COA obligations, they stay as they were.

Who has to report

Article 6 of the Regulation sets the threshold: 25,000 tonnes of CO2 equivalent a year, adding direct and indirect emissions from every fixed and mobile source of the establishment.

Where the line is drawn depends on the sector, and this is what confuses people most:

Sector	How it adds up
Energy and industry	Per facility. Each plant is assessed on its own
Transport, agriculture, waste, commerce and services	Adding every facility of the company

The sectors and subsectors are in articles 3 and 4. Industry covers chemicals, steel, metallurgy, metalworking, mining, automotive, pulp and paper, printing, petrochemicals, cement and lime, glass, electronics, electrical, food and beverages, wood and textiles. Commerce and services includes construction, wholesale and retail, higher education, hotels, hospitals, government offices, commercial banking and real estate.

Direct emissions are those of your own or leased fixed and mobile sources. Those of a contracted hauler do not count. Indirect emissions are those of the electricity and thermal energy you buy.

If a services company with many branches stays below the threshold, it does not report to the RENE. But article 24 is clear: it remains bound by whichever federal or state registries apply to it, and several states already levy carbon taxes with far lower thresholds.

Which gases

Article 5 lists fourteen items: carbon dioxide, methane, nitrous oxide, black carbon or soot, CFCs, HCFCs, HFCs, PFCs, sulfur hexafluoride, nitrogen trifluoride, halogenated ethers, halocarbons, their mixtures, and whichever others the IPCC determines and SEMARNAT publishes by agreement.

For a typical plant, three matter: the CO2 from fuels and electricity, the methane and nitrous oxide from combustion, and the HFCs from refrigeration and air conditioning equipment.

What is declared

Articles 9 and 14 detail the information by source type:

Fixed sources: direct emissions by gas, grouped by activity type, the annual volume consumed by fuel type and the location of the establishment.
Mobile sources: direct emissions by gas, the number and type of vehicles, and the annual volume by fuel type.
Indirect emissions: those from electricity and thermal energy consumption.

The RFC, the SCIAN code of the main activity, the legal representative and the reporting period go with it. If the establishment started operating after January 1, the period is irregular and runs from that day to December 31.

The dates

Everything happens in one window: from March 1 to June 30 each year, with the previous year's data. Article 12 says so.

After receiving the COA, SEMARNAT has 20 working days to review it. It can ask you once to complete or clarify information, and you have 15 working days to answer. If you do not, the greenhouse gas section is treated as not filed.

Two more deadlines worth noting. Article 9 requires keeping the data and documents you calculated with for five years, counted from the day SEMARNAT received the COA. And article 11 lets you correct an error already on record with a free-form notice, as long as you do it before PROFEPA opens an inspection.

How it is calculated

Article 7 sets two routes. The general one is multiplying activity data by emission factors, and it applies to combustion, processes, electricity and wastewater. The second is the material balance, for fluorinated compounds: refrigeration equipment, foams, aerosols and fire extinguishers.

SEMARNAT publishes three pieces you need every year:

The RENE emissions calculator, now at version 9.0, updated in March 2025.
The notice with the emission factor of the National Electricity System. The 2024 one was 0.444 tCO2e per MWh, published on February 28, 2025.
CONUEE's list of fuels and their calorific values, used to convert liters and cubic meters into energy.

The global warming potentials for converting each gas into CO2 equivalent are in a ministerial agreement. If your corporate inventory already follows the GHG Protocol, the activity data is the same; what changes are the factors, which here are set by the authority. The GHG Protocol and ISO 14064 guide explains how scopes map to direct and indirect emissions.

Verification

Every three years the report carries a Verification Opinion. Article 16 requires it and sets its window: from July 1 to November 30 of the year it falls due. The body reviews the emissions of the year before the report.

The opinion is issued by a body accredited by an accreditation entity and approved by SEMARNAT. PROFEPA publishes the list of approved bodies, with names such as ICONTEC, KPMG Cárdenas Dosal, TÜV Rheinland de México, TÜV SÜD, AENOR Confía and the Instituto Mexicano del Petróleo. Ask for the approval number before hiring.

Article 23 says what the verifier checks: that you used the right methods, that the factors and technical variables are appropriate, and that the information behind each figure is truthful. In other words, it will ask for the fuel and electricity invoices, the recharge logs and the fleet records.

Fines

Article 115 of the General Climate Change Law punishes two things: filing false information and missing deadlines. The fine runs from 3,000 to 10,000 days of minimum wage, today calculated with the UMA, and PROFEPA imposes it.

PROFEPA can also inspect the establishment to check that the methods are applied correctly. If it asks for the data and documents behind the report, you have 15 working days to hand them over.

What comes next

Two things are being built on top of the RENE.

The first is the Emissions Trading System. Its pilot program started on January 1, 2020 for energy and industry facilities emitting more than 100,000 tonnes of CO2 a year, around 300 from 90 groups. In September 2026, at the Mexico Carbon Forum, SEMARNAT said the system stops being a learning exercise and enters its operational phase, and the press reported 2027 as the start date. The auction rules are still pending.

The second is state carbon taxes. Several states have levied them for years, and Mexico City joined on January 1, 2025 with a rate of 58 pesos per tonne for fixed sources from one tonne of CO2 equivalent a month, far below the RENE. If your plant is in one of those states, the inventory you prepare for the COA is the same one you will need for the state return.

If you are close to the threshold

Measure the full year even if you think you fall short. The threshold is assessed on the year's total, and a growing plant or an expanding fleet can cross it without anyone noticing until March.

Keep the invoice behind every figure. Verification comes every three years, but a PROFEPA inspection can come sooner, and the five-year retention clock starts with every COA.

Grumbic calculates emissions from your fuel and electricity invoices, classifies them as direct or indirect and keeps every figure linked to the document it came from. That backing is what the verifier reviews and what PROFEPA asks for.

See the platform or talk to us.

Sources

Information reviewed on October 17, 2026 in documents from SEMARNAT, PROFEPA and the Diario Oficial de la Federación. This guide is informative and does not replace legal advice.