Brazil, Chile and Mexico on ISSB standards: three timetables after Chile's delay

Chile's securities regulator has pushed back mandatory reporting under the International Sustainability Standards Board's (ISSB) standards by a year, so the first reports will cover annual periods starting in 2027 and be published in 2028. The change, announced by the Financial Market Commission (CMF) in July, is recorded in the IFRS Foundation's jurisdictional profile of Chile, updated on 8 September 2026. It leaves three of the Latin American jurisdictions the Foundation has profiled on three different timetables, with three different answers on assurance, according to the Foundation's profiles, which it lists on its use-by-jurisdiction page, last updated on 24 September.

All three apply IFRS S1, the general requirements, and IFRS S2, the climate standard. The differences lie in who must report, when, how the standards enter local law and how much assurance is required.

Mexico: first reports already filed, assurance phased in

Mexico is the furthest advanced. The National Banking and Securities Commission (CNBV) amended its general provisions for issuers, known as the Circular Unica de Emisoras (CUE), in January 2025, incorporating the ISSB standards by reference, including all future ISSB standards, according to the Mexico profile. The changes took effect on 29 January 2025, and all issuers other than financial institutions, states and municipalities must present sustainability-related financial information for the first time in 2026, for the 2025 financial year.

Financial institutions are outside the requirement for now. The non-financial issuers within scope represented 86 per cent of the market capitalisation of the IPC, Mexico's main equity index, at the end of the first quarter of 2025, and the CNBV is analysing how to set equivalent requirements for financial institutions, the profile says.

Assurance is phased in. Reports published in 2026 for 2025 need none, reports published in 2027 for 2026 need limited assurance, and reports from 2028 for the 2027 financial year onwards need reasonable assurance, under ISSA 5000 or ISAE 3000 (revised), according to the profile. Mexico does not allow dual reporting and requires an explicit statement of compliance with the standards as issued by the ISSB.

Brazil: local translations and the strictest assurance

Brazil adopts the standards through CBPS 01 and CBPS 02, Portuguese translations of IFRS S1 and IFRS S2 issued by the Brazilian Sustainability Pronouncements Committee (CBPS), and makes them mandatory through resolutions of three authorities: the Securities and Exchange Commission (CVM), the National Monetary Council (CMN) and the Central Bank of Brazil (BCB), according to the Brazil profile.

CVM Resolution 193 of October 2023 set the path for listed companies: voluntary use from 2024, and CBPS standards required for financial years beginning on or after 1 January 2026 for publicly held companies. For banks, CMN Resolution 5,185 and BCB Resolution 435 make the standards mandatory from 2026 for publicly held companies and for the leaders of prudential conglomerates in segments S1 and S2, and from 2028 for other institutions that publish consolidated statements under international standards, the profile says. Segment S1 covers institutions whose total exposure equals or exceeds 10 per cent of GDP, and S2 those between 1 and 10 per cent.

Brazil is the only one of the three to require reasonable assurance from the start of the mandatory period, with limited assurance during the voluntary phase. Its first-year deadlines are also distinct: in the first mandatory year, listed companies publish within five months of the year end, on the same date as CVM's Reference Form, and in the second year within three months or with the financial statements, whichever is earlier, according to the profile. Brazil permits dual reporting against both the CBPS and the ISSB standards.

The profile carries a caveat. A notice dated 25 June 2026 says the CVM issued Resolution CVM 244 on 29 May 2026, altering some aspects of Resolution CVM 193, and that some of the information in the profile is out of date and under review. The notice does not say which aspects changed.

Chile: from TCFD and SASB to ISSB, a year later

Chile came to the ISSB standards through an earlier regime. CMF General Rule No. 461 of November 2021 required disclosures in the annual report using the recommendations of the Task Force on Climate-related Financial Disclosures (TCFD) and the SASB standards from 2022, phased in by size and sector. General Rule No. 519 of October 2024 then required CMF-regulated entities to apply IFRS S1 and IFRS S2 as issued by the ISSB from annual periods starting in 2026, reported in 2027, according to the Chile profile. The July 2026 announcement moves that start to 2027, with first reports in 2028.

The mandate covers listed entities, apart from certain exempted entities, and non-listed publicly accountable entities supervised by the CMF. Disclosures sit in the integrated annual report, the Memoria Anual Integrada. Chile requires no assurance, although an entity that seeks it must name its provider, and it does not allow dual reporting, the profile shows. Unlike Mexico, Chile does not adopt future ISSB standards automatically; each would go through the CMF's own due process.

The profiles are prepared once a jurisdiction's approach is final and are reviewed with the relevant authorities and international audit firms, the IFRS Foundation says. It also states that they are for general guidance only, so the regulators' own texts remain the binding source for companies preparing their first reports.