Japan now has its own sustainability reporting rulebook. The Sustainability Standards Board of Japan (SSBJ) builds these rules to run alongside — and stay close to — the ISSB’s global baseline, so Japanese companies and their overseas investors can read the same numbers the same way.

This guide walks through what SSBJ Standards actually cover, how SSBJ writes and issues them, which SSBJ Standards exist today, and what changed with the Practical Standard issued on June 11, 2026, which addresses how companies can use Japan’s existing GHG Reporting System to meet SSBJ’s climate disclosure rules.

Background and Why SSBJ Standards Exist

The Sustainability Standards Board of Japan is the body responsible for writing Japan’s sustainability disclosure rules. It operates under the Financial Accounting Standards Foundation (FASF), the same parent organization that oversees the Accounting Standards Board of Japan.

SSBJ develops its standards under a formal rulebook of its own: the “Rules on the Due Process for the Development of Sustainability Disclosure Standards,” known as the Due Process Rules. Every SSBJ standard, exposure draft, and discussion paper has to pass through this process before it becomes official.

The goal behind SSBJ Standards is straightforward. Japan wants a national framework that mirrors the ISSB’s IFRS Sustainability Disclosure Standards closely enough that a global investor can compare a Tokyo-listed company to a London- or New York-listed one without translation problems — literal or otherwise.

The Four Types of SSBJ Standards

SSBJ organizes its output into four categories, and each one plays a different role:

The Climate Standard — SSBJ’s Theme-based Sustainability Disclosure Standard No. 2, “Climate-related Disclosures” — is the one most companies encounter first. It’s the standard behind the Practical Standard update covered later in this guide.

How a standard actually gets made

SSBJ’s due process is built to force genuine input before anything becomes official. Board meetings happen monthly and are generally open to the public, with recordings and most discussion papers published on the SSBJ website. Passing a standard needs three-fifths of Board members in favor, and if any member votes against, their reasoning is published inside the final document. Before finalizing most new or amended standards, SSBJ opens an Exposure Draft for public comment — typically two months or longer — and publishes every response received, along with the respondent’s name. Once a standard has been in effect for about two years, SSBJ runs a post-implementation review and can amend it if problems surface, following the same process all over again. A separate body, the Due Process Oversight Committee under the FASF, checks that SSBJ is following its own rules and receives a compliance report every time a material standard is issued or amended.

How closely SSBJ tracks ISSB

SSBJ Standards are built to sit as close to ISSB Standards as Japan’s existing regulatory environment allows. The jurisdictional relief mechanism referenced later in this guide is a direct example — SSBJ didn’t invent it, it adopted a mechanism ISSB Standards already provide and adapted it to Japan’s own GHG Reporting System. SSBJ formalizes this alignment through a published Schedule of Differences and Table of Concordance, both jointly confirmed with the IFRS Foundation after every update, giving companies reporting into both frameworks a fast way to see exactly where the two diverge.

SSBJ Standards Issued So Far

SSBJ has moved fast since its first release. Here’s the timeline:

SSBJ standards are published only in Japanese. For English speakers, SSBJ maintains a Schedule of Differences and Table of Concordance between ISSB Standards and SSBJ Standards, both updated after each new release and confirmed jointly by the FASF and the IFRS Foundation.

SSBJ Standards: The Phased Timeline

Issuing a standard and requiring companies to use it are two different things. Japan’s Financial Services Agency (FSA) sets the mandatory application schedule. The FSA laid out the full roadmap in its “Japanese Roadmap on Sustainability Disclosure and Assurance,” released January 8, 2026, and it phases companies in by size rather than switching on all at once.

The rollout applies first to Prime Market-listed companies on the Tokyo Stock Exchange, starting with the largest by market capitalization:

Market capitalization is calculated as the average across the last five fiscal year-ends, up to the most recent one — not a single snapshot, so a company can’t dip below a threshold briefly and expect to sit out its wave.

A few details matter beyond the table itself:

• Prime Market companies below ¥500 billion don’t have a mandatory date yet. The FSA has said their timeline will be set later, based on how disclosure practice and investor demand develop.
• Any company can adopt early, including unlisted firms — voluntary application has been open since the fiscal year ending March 2026, for organizations that want a head start before their mandatory wave arrives.
• Disclosures get filed inside Japan’s annual securities report (yūhō), not as a standalone sustainability report, which puts SSBJ disclosures under the same regulatory and audit scrutiny as financial statements from day one.
• A two-year transition relief exists: companies can publish their sustainability disclosures after their financial statements, rather than simultaneously, for their first two years under the standard.

Mandatory assurance runs on its own clock

Disclosure and assurance aren’t the same deadline. The FSA’s roadmap starts mandatory third-party assurance one year after each wave’s mandatory disclosure date — so a Wave 1 company facing mandatory disclosure for the fiscal year ending March 2027 faces mandatory assurance the following year.

A few specifics worth planning around:

• The assurance scope starts narrow. For the first two years, mandatory assurance is limited to specific information rather than the full disclosure. Whether the scope expands after year three will depend on how international assurance practice develops.
• Assurance providers must be registered, but the FSA is taking a profession-agnostic approach — both audit firms and other qualified assurance providers can register, provided they meet the requirements. Assurance isn’t reserved for statutory auditors alone.
• The same phased logic applies as disclosure: sustainability disclosures can run after the financial statements for the first two years, then shift to simultaneous disclosure once assurance requirements catch up.

For a Wave 1 company, the fiscal year ending March 2027 is now less than a year away — which is exactly why the Practical Standard’s GHG Reporting System guidance, covered next, is landing at a useful moment rather than an academic one.

Who Should Care About This

Two different scope questions are worth separating here. The market-cap timeline above determines who must apply SSBJ Standards at all. A second, separate threshold — under Japan’s GHG Reporting System — determines who counts as a “specified emitter,” which is the scope relevant to the Recent Update section below.

Japan’s Act on Promotion of Global Warming Countermeasures designates a company as a “specified emitter,” subject to mandatory GHG reporting, once it crosses either of two thresholds at a business site in Japan:

• Energy use above 1,500 kl of crude oil equivalent per year, or
• GHG emissions above 3,000 t-CO2 per year from business activities at that site.

Cross either threshold and the entity must calculate and report emissions annually to Japan’s Ministry of the Environment and Ministry of Economy, Trade and Industry — figures compiled company-wide across all its Japan sites, not just the single site that triggered the requirement. Roughly 12,000–14,000 companies report under this system each year, spanning manufacturing, energy, transportation, commercial real estate, and large commercial operators.

In practice, that means:

• Japan-based subsidiaries and manufacturing sites of multinational groups that run energy-intensive operations — factories, data centers, large office campuses — are the most likely to already be filing under the GHG Reporting System, whether or not their global parent has ever touched SSBJ’s Climate Standard.
• Companies below both thresholds aren’t specified emitters, so the GHG Reporting System simply doesn’t apply to them, regardless of whether they’re preparing SSBJ disclosures for other reasons.
• Prime Market-listed companies on the Tokyo Stock Exchange, which face separate climate disclosure expectations under Japan’s Corporate Governance Code, are especially likely to sit at the intersection of both requirements.

For global sustainability, procurement, and finance teams managing disclosures across multiple jurisdictions, this is exactly the kind of country-specific rule that determines whether consolidated group reporting holds together or breaks apart at the seams. If even one Japan entity crosses the 1,500 kl or 3,000 t-CO2 threshold, its emissions treatment under Japan’s rules affects the integrity of the whole group’s numbers.

Recent Update on SSBJ: The June 2026 Practical Standard

SSBJ itself has been in place since March 2025. Its most recent addition — Practical Sustainability Disclosure Standard No. 1, issued June 11, 2026 — solves one specific problem: how companies should use Japan’s existing GHG Reporting System to meet the Climate Standard’s emissions disclosure requirements.

Japan already runs its own mandatory GHG Reporting System under the Act on Promotion of Global Warming Countermeasures, with specified emitters calculating and reporting emissions to the government every year using government-prescribed methods. Once SSBJ’s Climate Standard arrived, the open question was whether companies could reuse that data or had to run a separate calculation for SSBJ purposes.

The short answer is yes, with conditions. SSBJ’s Climate Standard includes a “jurisdictional relief” — borrowed from the ISSB Standards — that lets entities use a different measurement method when a jurisdictional authority or stock exchange requires it. SSBJ has now confirmed that reporting under Japan’s GHG Reporting System qualifies for this relief.

What it requires:

• Scope 1 GHG emissions: The direct emissions already reported under the GHG Reporting System carry over with no additional adjustment, aside from aligning reporting periods.
• Scope 2 GHG emissions, market-based: The indirect emissions reported under the GHG Reporting System carry over the same way — no extra adjustment beyond period alignment.
• Scope 2 GHG emissions, location-based: Japan’s GHG Reporting System doesn’t require companies to report location-based Scope 2 emissions. But the Practical Standard allows companies to calculate them by taking the same activity data used for market-based reporting and multiplying it by the average emission factor the Japanese government publishes.

Companies applying the relief to only one scope — Scope 1 or Scope 2 — rather than both need to say so explicitly. Two groups sit outside this standard’s scope entirely: companies that only use GHG Reporting System data as an input to a separate GHG Protocol (2004) calculation, and any use of jurisdictional relief tied to schemes other than Japan’s GHG Reporting System specifically.

SSBJ built this standard after stakeholders flagged inconsistent interpretations of which emissions figures to use and how — left unresolved, that inconsistency threatened comparability between companies. SSBJ settled it in favor of the interpretation closest to the GHG Protocol Corporate Accounting and Reporting Standard, keeping the reporting burden proportional to what companies already collect for the government.

The standard applies to annual reporting periods ending on or after March 31, 2027. Earlier application is permitted, so companies already deep into Climate Standard preparation don’t have to wait to adopt it.

How Sprih Helps With SSBJ-Aligned Reporting

Everything above adds up to a real operational challenge: tracking Scope 1 and Scope 2 emissions data across every Japan entity, knowing which numbers qualify for jurisdictional relief, and getting disclosure-ready before your wave’s deadline arrives. Here’s concretely how Sprih’s AI Infrastructure for Sustainability, helps close that gap:

• Entity-level data organization. SustainSense keeps GHG data structured at the individual entity level, so a Japan subsidiary’s Scope 1 and Scope 2 figures roll up cleanly into consolidated group reporting instead of getting reconciled by hand each cycle.
• Dual-framework readiness. Because SSBJ and ISSB both anchor to the same GHG Protocol methodology, teams reporting into both frameworks can maintain one clean dataset instead of rebuilding calculations twice — data gets mapped once and applied across jurisdictions.
• Deadline and wave tracking. SustainSense flags which entities fall under which SSBJ wave or GHG Reporting System threshold, giving compliance and sustainability teams visibility into upcoming deadlines well before fiscal year-end.
• Audit-ready documentation. With mandatory third-party assurance arriving a year behind each disclosure deadline, having emissions data, source documentation, and calculation methods organized and traceable from day one matters — that’s built into how SustainSense structures data, not bolted on afterward.

If your organization is approaching a Wave 1, 2, or 3 deadline, or already filing under Japan’s GHG Reporting System, explore Sprih’s sustainability reporting resources or see how the Sprih Enterprise platform maps to your entity structure.