Japan's mandatory third-party assurance of corporate sustainability disclosures is starting narrow, and the Financial Services Agency wants it to stay that way for at least two years. Minutes from the second meeting of the FSA's Sustainability Information Assurance Subcommittee, held 3 July 2026, show the secretariat presenting an outline of the opinion paper it wants the panel to build, one that would confine compulsory assurance to Scope 1 and Scope 2 greenhouse-gas emissions, governance disclosures and risk-management disclosures, only part of the sustainability information companies will report under Japan's new SSBJ standards.
Even that narrow slice would get the lighter of the two assurance tiers. The outline the subcommittee is now discussing calls for "limited assurance," comparable to an interim review, and rules out any move to "reasonable assurance," the higher standard applied to financial-statement audits. The bigger structural change is who can do the work: a bill amending the Financial Instruments and Exchange Act, still pending in the Diet, would let any provider register as a sustainability assurance provider if it meets FSA requirements, whether or not it is a licensed audit firm.
To make that workable across two very different kinds of providers, the FSA plans to write the standards itself rather than adopt the Japanese Institute of Certified Public Accountants' existing assurance guideline outright. It will start from JICPA's practice guideline, adapt it so non-audit-firm providers can follow it, and align it with the IAASB's international ISSA5000 standard. The tentative names are JSSA5000 for the assurance standard, JSQM1 for quality management and JESSA for ethics and independence, all borrowing the "J" for Japan.
Two questions remain open. Some committee members want the definition of the "person responsible for governance" limited to audit-side bodies, statutory auditors, audit and supervisory committees, or audit committees, rather than the full board of directors, arguing that Japanese boards are usually majority-executive and so compromised as an independent counterpart; another member pushed back, saying the board should stay in the definition given how governance structures vary by company. Separately, one committee member asked the FSA to require securities reports to flag which disclosed figures actually carry an assurance opinion and which do not, since only part of the disclosure will be covered; FSA disclosure officials said they have no concrete plan yet and will consider it.
A preparer representative from Sony sitting on the panel asked the FSA to keep talking to the European Commission so Japanese companies with EU-exposed subsidiaries are not forced into duplicate reporting and duplicate assurance under the EU's Corporate Sustainability Reporting Directive. The subcommittee's opinion paper will only guide a future cabinet-office ordinance rather than take legal effect on its own, and the Financial Instruments and Exchange Act amendment it depends on has not yet passed the Diet.