ESG Ratings Regulation 2026: What Investors & Companies Should Know
Aymen Karoui, Ph.D., Head of Methodology, Inrate
Note: The views expressed on these pages are the opinions of their respective author(s) only and do not necessarily reflect the views and opinions of UKSIF.
This website should not be taken as financial or investment advice or seen as an endorsement or recommendation of any particular company, investment or individual. While we have sought to ensure information on this site is correct, we do not accept liability for any errors.
ESG Ratings Regulation 2026: What Investors & Companies Should Know
Aymen Karoui, Ph.D., Head of Methodology, Inrate
The time of ESG ratings as an informal reference may have officially ended. In 2026, ESG ratings will cease to occupy a regulatory grey zone, becoming regulated market instruments subject to a level of scrutiny approaching that of credit rating agencies. ESG ratings regulation is intended to promote transparency, integrity, and comparability of ESG rating activities.
This is not a cosmetic change for financial institutions. It represents a significant shift in the way sustainability risk and long-term value are integrated into capital markets.
The current article discusses the latest EU and UK ESG ratings regulations and what investors and companies should know in 2026.
Why ESG Regulation Became Necessary?
ESG ratings assess how companies manage material environmental, social, and governance risks and opportunities. Therefore, they offer investors essential insights for constructing portfolios and making decisions aligned with social and environmental principles.
However, ESG ratings have long been characterized by limited transparency in methodologies and some inconsistencies in the underlying data. Another issue pertains to possible conflicts of interest between rating and advisory activities, and a lack of clarity around accountability mechanisms.
Taken together, the need to better support market participants while addressing current shortcomings has made it necessary to establish a more formal regulatory framework.
EU ESG Ratings Regulation: A New Supervisory Framework
Formally adopted in November 2024, the EU ESG ratings regulation has created a binding regulatory framework for providers of ESG ratings to the EU market. It entered into force on 2 January 2025, will apply from July 2026, and will be overseen by the European Securities and Markets Authority (ESMA). Below are the key pillars of the EU ESG ratings regulation:
1. Mandatory authorisation and supervision
ESG rating providers are required to be registered with ESMA and to meet ongoing supervisory requirements.
2. Transparency of methodologies and data sources
The ESG rating providers should make clear disclosures of their:
- • Rating objectives and scopes.
- • Weighting logic and methodologies
- • Sources of data and methods of estimation.
3. Management of conflict of interest
Providers should not confuse ESG ratings with consulting or advisory services that may violate independence.
4. Provisions for third-country providers
Non-EU ESG rating agencies are allowed to carry on with their operations in Europe through equivalence, recognition, or endorsement, which ensures continuity in the markets globally.
UK ESG Ratings Regulation: A Principles-Based Approach
Although the EU and UK ESG rating regulations share similar goals, the UK regulation offers more flexibility. The UK Financial Conduct Authority (FCA) has suggested a regulatory framework based on the International Organization of Securities Commissions (IOSCO) principles with a view to governance, transparency, and resilience in operations as opposed to prescriptive standardisation.
Final FCA rules are expected in late 2026, with ESG ratings becoming a regulated activity from 29 June 2028, followed by a transition period into 2029.
The UK framework focuses on ensuring strong accountability and governance structures, promoting transparency in methodologies and assumptions, managing potential conflicts of interest, and clearly communicating any limitations or restrictions associated with ESG ratings.
Why ESG Ratings Regulation Matters for Financial Institutions?
ESG Ratings Regulation is not merely a compliance exercise; it is increasingly a strategic priority for financial market participants. It can deliver several benefits:
- Stronger investment decision-making: By enhancing trust in the sustainability indicators used in investment and risk management.
- Better regulatory alignment: By minimizing the legal and reputational risks, increasing transparency, and improving standardization.
- Enhanced due diligence: By supporting more rigorous assessment and governance of third-party vendors.
What Will Change for Financial Institutions?
The ESG ratings regulation will require financial institutions to adjust key internal processes. They will need to strengthen vendor governance by verifying ESG rating providers’ authorisation, understanding methodological differences, and documenting how ratings are used.
At the same time, product governance will be reinforced, with greater emphasis on tracing ESG data sources and ensuring the underlying information is transparent, well documented, and fit for investment and risk use.
Challenges and Trade-Offs in ESG Ratings Regulation
While ESG ratings regulation strengthens trust and accountability, it also introduces important trade offs.
- • Transparency vs. proprietary innovation: Providers must enhance methodological transparency without undermining intellectual.
- • Comparability vs. diversity of opinion: Greater disclosure should improve understanding of ratings without eliminating differences in ESG assessments.
- • Cross border alignment: International providers will continue to face regulatory fragmentation in the short term.
Strategic Takeaways for Investors and Companies
As ESG ratings become regulated market instruments, financial institutions will need to reassess their ESG rating providers and ensure they are prepared for regulatory oversight. They will also need to strengthen internal ESG data governance and train investment and risk teams to interpret regulated ratings effectively. Finally, they must align their broader sustainability strategies with evolving regulatory expectations.
The views expressed on these pages are the opinions of their respective author(s) only and do not necessarily reflect the views and opinions of UKSIF.
This website should not be taken as financial or investment advice or seen as an endorsement or recommendation of any particular company, investment or individual. While we have sought to ensure information on this site is correct, we do not accept liability for any errors.
