Japan has enacted a new sustainability reporting mandate requiring certain listed companies to prepare sustainability disclosures under the Sustainability Standards Board of Japan (SSBJ) standards and submit them digitally using Inline XBRL.
The first mandatory reporting phase will apply to Tokyo Stock Exchange Prime Market companies with a market capitalisation of at least ¥3 trillion for financial years beginning on or after 1 April 2027. The framework also introduces assurance requirements for sustainability information.
Japan Sustainability Reporting Mandate: Key Facts
| Requirement | Details |
|---|---|
| Reporting framework | Sustainability Standards Board of Japan standards |
| Digital reporting format | Inline XBRL |
| Filing system | EDINET |
| First companies in scope | Tokyo Stock Exchange Prime Market companies with market capitalisation of at least ¥3 trillion |
| Effective date | Financial years beginning on or after 1 April 2027 |
| Additional requirement | Assurance over sustainability information |
What Has Japan Announced?
On 15 July 2026, the Japanese Diet enacted amendments to the Financial Instruments and Exchange Act and the Payment Services Act.
The legislation, which was submitted on 10 April 2026, introduces measures covering several areas, including sustainability disclosure and assurance. According to Japan’s Financial Services Agency, the reforms are intended to improve market fairness and transparency while strengthening investor protection.
For companies covered by the sustainability provisions, the legislation brings together three connected requirements:
- reporting under Japanese sustainability disclosure standards;
- assurance over sustainability information; and
- digital submission using Inline XBRL.
This means sustainability reporting in Japan will become both a disclosure obligation and a structured digital reporting requirement. This mirrors the direction of travel in other major markets, where digital tagging has become integral to sustainability disclosure — as seen in the EU’s CSRD and ESRS regime and India’s Business Responsibility and Sustainability Reporting (BRSR) framework.
Who Must Report Under Japan’s Sustainability Reporting Mandate?
The first mandatory reporting phase will apply to companies that:
- are listed on the Tokyo Stock Exchange Prime Market; and
- have a market capitalisation of at least ¥3 trillion.
These companies will need to comply for financial years beginning on or after 1 April 2027.
The reporting requirements are expected to extend to additional Prime Market-listed companies over time. Further implementation measures will determine the detailed timetable and requirements for later reporting groups. For more background on Japan’s adoption of ISSB-aligned standards, see our overview of Japan’s ISSB-aligned sustainability reporting.
When Does Mandatory Sustainability Reporting Begin in Japan?
Mandatory reporting begins for the first group of companies for financial years starting on or after 1 April 2027.
For a company whose financial year begins on 1 April, the first reporting period would therefore run from 1 April 2027 to 31 March 2028.
The first phase is expected to affect approximately 70 companies listed on the Tokyo Stock Exchange Prime Market with an average market capitalisation of ¥3 trillion or more. The Financial Services Agency’s published estimate identified 68 companies based on market data available as of 29 March 2024. The final number may vary because eligibility is determined using the company’s average market capitalisation at the previous five fiscal year-ends.
Companies within the first phase should use the period before implementation to assess their:
- SSBJ reporting readiness;
- sustainability data availability;
- internal controls;
- assurance evidence;
- digital tagging processes; and
- governance and approval workflows.
Which Sustainability Standards Will Japanese Companies Use?
Companies within scope will prepare their disclosures using standards issued by the Sustainability Standards Board of Japan, commonly known as the SSBJ.
The SSBJ standards are based closely on the International Sustainability Standards Board’s global disclosure standards:
- IFRS S1: General Requirements for Disclosure of Sustainability-related Financial Information
- IFRS S2: Climate-related Disclosures
Japan’s standards also contain jurisdiction-specific provisions and alternatives designed for the Japanese reporting environment.
The alignment with IFRS S1 and IFRS S2 is intended to support greater international comparability while allowing Japan to address domestic reporting considerations.
Is Inline XBRL Mandatory for Sustainability Reporting in Japan?
Yes. Companies covered by the new mandate will be required to prepare digitally structured sustainability disclosures using Inline XBRL, or iXBRL.
Inline XBRL combines:
- a human-readable report that can be viewed in a browser; and
- machine-readable tags that allow individual disclosures and data points to be digitally identified.
This enables sustainability information to be searched, extracted, validated and compared more efficiently by investors, regulators and other data users.
Japan is therefore introducing structured digital reporting as an integral part of its sustainability reporting framework rather than treating tagging as a separate future requirement.
How Will Sustainability Reports Be Filed?
The Japanese Financial Services Agency is working to integrate sustainability reporting requirements into EDINET, Japan’s electronic corporate disclosure platform.
This work includes incorporating the IFRS Sustainability Disclosure Taxonomy into the EDINET environment.
The final filing framework will need to connect:
- SSBJ-aligned disclosures;
- the applicable digital taxonomy;
- Inline XBRL tagging;
- technical and business validations; and
- submission through EDINET.
Companies will therefore need processes that address both the content of their sustainability disclosures and the technical requirements of digital regulatory filing.
Will Sustainability Disclosures Require Assurance?
Yes. The new legislation introduces assurance requirements for sustainability information. According to the FSA’s roadmap on sustainability disclosure and assurance, mandatory assurance will begin one year after the mandatory application of the SSBJ standards, with the assurance scope initially limited to specific information.
Assurance increases the importance of maintaining reliable evidence behind reported data, methodologies, estimates and management judgements.
Companies will need to demonstrate:
- where reported information originated;
- how calculations were performed;
- which assumptions were used;
- who reviewed and approved each disclosure;
- how changes were controlled; and
- whether the final report remains consistent with supporting evidence.
Detailed assurance requirements and their implementation are expected to be clarified through further regulations and guidance.
What Does the Japan Sustainability Reporting Mandate Mean for Companies?
The new mandate affects more than the final sustainability report. It requires companies to connect reporting standards, source data, evidence, assurance and digital tagging within a controlled reporting process.
1. SSBJ Readiness Assessment
Companies should compare their existing sustainability disclosures with the SSBJ standards and identify missing disclosures, data and governance processes.
2. Financial and Sustainability Data Alignment
Sustainability-related financial information should remain consistent with financial statements, management reports and other corporate disclosures. A unified financial and ESG disclosure approach helps maintain this consistency across the reporting cycle.
3. Structured Data Collection
Reporting teams will need controlled processes for gathering climate, financial and other sustainability information from business functions and subsidiaries.
4. Inline XBRL Tagging
Disclosures must be mapped to the appropriate taxonomy concepts and prepared in a format that meets EDINET filing requirements.
5. Assurance Evidence
Source documents, calculations, methodologies, assumptions and review records should be retained alongside reported information.
6. Review and Approval Governance
Clear ownership, role-based reviews, version control and approval workflows will be necessary to support accountability.
7. Validation and Filing Readiness
Companies will need to perform disclosure, data and technical validations before submitting their reports.
Why Should Companies Begin Preparing Before 2027?
The reporting date may begin in 2027, but the information required for the first report will need to be collected throughout the reporting period.
Companies that wait until the end of the reporting cycle may face difficulties relating to:
- missing source data;
- unsupported calculations;
- inconsistent financial and sustainability information;
- incomplete audit evidence;
- late taxonomy mapping;
- tagging errors; and
- limited time for review and assurance.
Early preparation allows companies to test data collection, define ownership, assess SSBJ gaps and integrate Inline XBRL into the reporting workflow before the first mandatory filing.
How EcoActive Supports Japan’s Sustainability Reporting Requirements
EcoActive is an AI-native platform for unified financial and sustainability disclosure management. It helps organisations manage reporting requirements, data, evidence, review and digital reporting within one governed environment.
SSBJ and ISSB-Aligned Reporting
Organise disclosures around applicable SSBJ requirements and maintain clear connections between reporting obligations, responses, source data and evidence.
Unified Financial and Sustainability Information
Connect sustainability disclosures with the financial figures and supporting information used across the reporting cycle, helping improve consistency between financial and sustainability reports.
Structured Data Collection
Collect information from departments, subsidiaries and data owners through controlled workflows with clearly assigned responsibilities and deadlines.
Continuous Validation
Identify missing information, inconsistencies and potential reporting gaps throughout the reporting process rather than waiting until the final review.
Evidence and Assurance Readiness
Retain source documents, methodologies, calculations, judgements and approval histories alongside each disclosure.
Inline XBRL-Ready Reporting
Integrate digital tagging into the disclosure preparation workflow so that structured reporting is developed alongside the report rather than added at the end.
Governed Review and Approval
Use role-based access, version control, structured reviews and complete audit trails to support accountability and assurance.
Impact-Aware Change Management
Understand how a change to a financial or sustainability data point affects connected disclosures, calculations, narratives and digital tags.
Building Digital Sustainability Reporting into the Process
Japan’s sustainability reporting mandate brings SSBJ disclosures, assurance and Inline XBRL into a connected regulatory framework.
For companies within scope, compliance will require more than preparing a sustainability report. Organisations will need governed processes that connect reporting requirements, data, evidence, financial information, review and machine-readable filing.
EcoActive helps organisations build these requirements into the reporting lifecycle from the beginning—supporting consistent, assurance-ready and digitally structured sustainability disclosures.
Preparing for Japan’s SSBJ, assurance and Inline XBRL requirements?
Frequently Asked Questions
Is sustainability reporting mandatory in Japan?
Japan has enacted mandatory sustainability disclosure requirements for certain listed companies. The first phase applies to Tokyo Stock Exchange Prime Market companies with market capitalisation of at least ¥3 trillion.
When does mandatory sustainability reporting begin in Japan?
The first phase applies to financial years beginning on or after 1 April 2027.
Which standards will apply to sustainability reporting in Japan?
Companies within scope will use sustainability disclosure standards issued by the Sustainability Standards Board of Japan. The standards are closely aligned with IFRS S1 and IFRS S2.
Is Inline XBRL required for Japanese sustainability reports?
Yes. Sustainability disclosures covered by the new mandate will need to be digitally tagged using Inline XBRL.
Where will Japanese sustainability reports be filed?
The disclosures will be integrated into EDINET, Japan’s electronic corporate disclosure system.
Will sustainability disclosures in Japan require assurance?
Yes. The legislation introduces assurance requirements for sustainability information, although additional implementation details are expected through further regulations and guidance.
What should companies do to prepare?
Companies should assess SSBJ reporting gaps, establish structured data collection, strengthen internal controls, prepare supporting evidence and integrate Inline XBRL into the reporting workflow.
