Scope 3 in Mexico: The Deadline Is Next Year — Is Anyone Ready?

With the introduction of ISSB (IFRS) regulatory reporting standards in Mexico, many issuers who have never conducted an emissions inventory are realizing that by 2027 they will be required to report Scope 3 emissions. Furthermore, the report that includes those emissions will need to undergo limited assurance. What does this mean? In short, issuers face a dual challenge simultaneously: Scope 3 emissions data must exist and be defensible to an external auditor, within the same reporting cycle. 

What Are Scope 3 Emissions?  

According to the GHG Protocol, Scope 3 emissions are a consequence of a company’s activities but arise from sources that are neither owned nor directly controlled by the company. There are 15 distinct Scope 3 categories, divided into two broad groups: upstream and downstream emissions. Identifying which of these categories are material to each company is the first and most important step. 

When it comes to adding these emissions to the inventory, several challenges must be sorted out: dependence on suppliers, tenants, and logistics partners; informal-sector suppliers with no ESG capacity; and the risk of double counting, among others. 

What actions should issuers be taking to be ready? 

1. Map the value chain and assign categories. 
2. Run a materiality and data-availability screen (including an inventory of existing internal data). 
3. Segment suppliers by emissions relevance and launch targeted data requests to the most significant ones. 
4. Build the calculation model, documenting every assumption used. 
5. Draft the final disclosure. 

Those who take advantage of this year to build a Scope 3 data pipeline will walk into that report with a credible, defensible number. Those who wait until 2027 will be trying to build a year’s worth of methodology in the months before filing, under assurance scrutiny, with no margin for error. 

Scope 3 will never be perfect on the first attempt, and it doesn’t need to be — but it does need to be real, structured, and honest about what’s estimated versus verified. Are you already prepared?  

 I hope you found this interesting. As usual, if there is anything we can help you with, or if there is an ESG topic you would like to know more about, please let us know. 

Best,

Marimar

CEO, Miranda ESG