South Korea will expand mandatory ESG disclosure from fewer than 300 entities to more than 3,000 within a year of its 2028 launch. The Financial Services Commission's (FSC) roadmap rapidly increases the number of covered entities, including consolidated affiliates, from 291 in 2028 to 3,171 in 2029.

South Korea’s disclosure regime is notable for its speed, extending reporting across the listed market, increasing data availability for investors though creating short-term challenges around consistency, comparability and enforcement.

Narrow starting point to wider market coverage

The regime will begin in 2028 with KOSPI-listed companies holding at least KRW10 trillion (U$6.7 trillion) in assets, capturing 291 issuers and affiliates in its first year. However, coverage will broaden dramatically in 2029, when the threshold falls to KRW5 trillion and the number of obligated companies increases to 3,171.

A further review could extend the requirement to companies with KRW2 trillion in assets from 2030, suggesting that ESG disclosure may become a standard expectation across much of the Korean listed universe within a few years.

The ESG disclosure rules in South Korea are long-awaited, with plans initially being set in 2021 for them to come into effect in 2023. However, the FSC postponed their implementation until after 2026 following the delay of such rules coming into effect in other jurisdictions.

The FSC noted that institutional investors had requested an expansion in the scope of disclosure entities considering the usefulness of sustainability disclosure data for investment purposes. It had consulted on the sustainability disclosure rules with stakeholders including institutional investors, non-governmental organisations, professional groups, industry groups and businesses.

Embedding disclosure into core reporting

The expansion is reinforced by how disclosures will be delivered. ESG information will be included within corporate business reports under securities law, placing it alongside financial statements and elevating its importance within company reporting.

This approach ensures that the growing number of covered companies is not only larger, but also subject to a consistent and formalised reporting structure. As a result, ESG disclosure will move swiftly from a niche requirement for large issuers to a mainstream obligation across listed companies.

Managing scale through phased requirements

The regulator has introduced measures to support the expansion in coverage. Companies will be allowed to exclude smaller affiliates in their first year of reporting and will benefit from a three-year exemption from liability tied to ESG disclosures.

These provisions reflect the operational challenges of scaling reporting requirements across thousands of companies in a compressed timeframe. At the same time, authorities have made clear that intentional greenwashing will still be enforced, signalling an attempt to balance speedy expansion with credibility.

Scope 3 emissions disclosures are expected to be phased in after a three-year transition period, with reporting for the largest companies anticipated from FY2030 onwards. This staged approach indicates that while coverage will expand quickly, the depth of disclosure will increase more gradually.

Implications for investors

For investors, the most immediate impact is the scale of new ESG data that will become available. The jump from fewer than 300 to more than 3,000 companies within a year represents a material shift in coverage, enabling broader portfolio analysis and comparability across the Korean market.

South Korea’s rapid expansion contrasts with the EU’s phased ESG disclosure rollout and Japan’s gradual approach. The EU’s Corporate Sustainability Reporting Directive extends coverage in stages based on company size and listing status, prioritising consistency. Japan has expanded disclosure expectations incrementally through governance reforms and alignment with frameworks such as TCFD.

However, the pace of expansion also introduces challenges. As many companies enter the regime simultaneously, disclosure quality is likely to vary, particularly during the three-year liability relief period. Differences in methodology, scope and underlying data may complicate comparisons between issuers.

This dynamic places greater emphasis on investor scrutiny and engagement. With ESG disclosures becoming standard across a wider set of companies, investors will need to focus not only on the presence of data, but on its reliability and consistency.

Alongside the expansion of ESG disclosure, South Korea has advanced a parallel programme of corporate governance reform aimed at improving transparency and shareholder outcomes. These reforms form part of a broader effort to strengthen market discipline and align corporate behaviour more closely with investor expectations, reinforcing the role of ESG disclosure as one component of a wider shift in governance standards rather than a standalone initiative.

What’s next

South Korea’s ESG disclosure regime is defined less by its start date than by how quickly it scales. The rapid expansion to thousands of companies signals a clear regulatory objective to normalise ESG reporting across the market within a short timeframe.

For companies, this means ESG disclosure will quickly become a standard requirement rather than a differentiating practice. For investors, it offers a significant increase in available data, but one that will require careful interpretation as the system matures.