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.

What Is the Sustainability Standards Board of Japan (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:

Standard type	What it covers
Universal Sustainability Disclosure Standards	The overall structure and basic rules underlying every other SSBJ standard
Theme-based Sustainability Disclosure Standards	General sustainability disclosures and specific themes, such as climate
Industry-based Sustainability Disclosure Standards	Disclosures tailored to individual industries
Practical Sustainability Disclosure Standards	Narrow, practical clarifications that don’t fit cleanly into the other three categories

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 SSBJ Actually Writes a Standard

SSBJ’s due process isn’t a formality. It’s built to force genuine input from the companies, auditors, and investors who will eventually use the standards.

Board meetings happen monthly, and they’re generally open to the public. Video recordings go up on the SSBJ website, and most discussion papers are published too — the exceptions are drafts of exposure drafts and final standards still in progress.

Passing a standard takes a real majority. SSBJ needs three-fifths of its Board members to vote in favor before it can issue a Sustainability Disclosure Standard, an Exposure Draft, or a Discussion Paper. If a Board member votes against a standard, their reasoning gets published inside the final document — nothing gets buried.

Exposure drafts invite outside comment. Before finalizing most new or amended standards, SSBJ publishes an Exposure Draft and opens a comment period of two months or longer, unless the Board votes to shorten it for time-sensitive proposals. Every response received, along with the respondent’s name, goes up on the SSBJ website.

Standards get checked after they launch. Once a new or materially amended standard has been in effect for about two years, SSBJ conducts a post-implementation review to see how it actually performed for investors, preparers, and auditors. If the review turns up problems, SSBJ can amend the standard — following the same due process all over again.

A separate committee watches SSBJ itself. The Due Process Oversight Committee, set up by the FASF, checks that SSBJ is following its own rules. SSBJ reports to this committee every time it issues or amends a material standard, plus an annual compliance summary.

SSBJ Standards Issued So Far

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

Date	Standard
March 5, 2025	Inaugural Sustainability Disclosure Standards applied in Japan
March 13, 2026	Amendments to three standards, aligning with the ISSB’s amendments to IFRS S2 on greenhouse gas disclosures
June 11, 2026	Practical Sustainability Disclosure Standard No. 1, on using Japan’s GHG Reporting System to comply with the Climate Standard

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.

When Do SSBJ Standards Become Mandatory? 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:

Wave	Market Capitalization	Mandatory From (Fiscal Year Ending)
Wave 1	¥3 trillion or more	March 2027
Wave 2	¥1 trillion to under ¥3 trillion	March 2028
Wave 3	¥500 billion to under ¥1 trillion	March 2029

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.

The June 2026 Practical Standard, Explained

This is the update companies are asking about right now, and it solves a real problem.

Japan already runs its own mandatory GHG Reporting System under the Act on Promotion of Global Warming Countermeasures. Companies that meet certain energy-use and emissions thresholds have to calculate and report their GHG emissions to the Japanese government every year, using government-prescribed calculation methods and emission factors.

Once SSBJ’s Climate Standard arrived, a question followed close behind: can companies just reuse the numbers they already report to the government, or do they need 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 the Practical Standard actually requires

Companies that apply the jurisdictional relief and use GHG Reporting System data must disclose their emissions in a specific structure:

• 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. That result can then be used directly for location-based disclosure.

If a company applies the jurisdictional relief to only one scope — Scope 1 or Scope 2 — rather than both, it needs to say so explicitly in its disclosures.

One more technical point worth flagging: emissions disclosed this way are treated as measured using a method other than the GHG Protocol (2004) for the purposes of any other Climate Standard disclosure requirements that depend on measurement method.

Why SSBJ built this standard

Before this update, stakeholders had told SSBJ that interpretations were splitting in three different directions: whether to use non-adjusted or adjusted emissions figures, whether GHG Reporting System data could count as location-based Scope 2 emissions under the jurisdictional relief, and whether companies using the relief for market-based Scope 2 emissions also had to separately measure location-based emissions.

Left unresolved, those splits threatened the one thing sustainability disclosure is supposed to deliver: comparability. Two companies in the same industry could have ended up reporting materially different numbers for reasons that had nothing to do with their actual emissions. SSBJ closed that gap directly, choosing the interpretation that stays closest to the GHG Protocol Corporate Accounting and Reporting Standard and keeps the reporting burden proportional to what companies already collect for the government.

Effective date

The Practical 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.

Who Should Care About This

Two different scope questions are at play here, and they’re easy to conflate. The market-cap timeline above determines who must apply SSBJ Standards at all. The Practical Standard only matters on top of that — it’s relevant once you’re already inside Japan’s GHG Reporting System, regardless of which SSBJ wave you fall into.

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 — and therefore this Practical Standard — 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.

It also matters for two groups the Practical Standard explicitly doesn’t cover:

• Companies that measure emissions directly under the GHG Protocol (2004) and only use GHG Reporting System data as an input, adjusting it afterward, fall outside this standard’s scope.
• The Practical Standard says nothing about jurisdictional relief under schemes other than Japan’s GHG Reporting System — so it can’t be stretched to cover other national emissions schemes.

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 Scope 1 and Scope 2 treatment under this Practical Standard affects the integrity of the whole group’s numbers.

SSBJ and ISSB: How Closely Do They Track Each Other?

SSBJ Standards are built to sit as close to ISSB Standards as Japan’s existing regulatory environment allows. The jurisdictional relief mechanism is a direct example — SSBJ didn’t invent it, it adopted a mechanism the ISSB Standards already provide and then clarified exactly how it applies to a Japan-specific reporting system.

SSBJ formalizes this alignment work through its published Schedule of Differences and Table of Concordance, both jointly confirmed with the IFRS Foundation after every update. For companies reporting into both frameworks, these documents are the fastest way to see exactly where SSBJ diverges from ISSB, and where it doesn’t.

How Sprih Helps With SSBJ-Aligned Reporting

Tracking Scope 1 and Scope 2 emissions data across a multi-entity group — and knowing which numbers qualify for which jurisdictional relief — is exactly the kind of work Sprih’s AI Infrastructure for Climate and Sustainability is built to carry. SustainSense keeps disclosure-ready GHG data organized at the entity level, so teams reporting into SSBJ, ISSB, or both aren’t rebuilding the same numbers twice. Explore more on Sprih’s sustainability reporting resources or see how the Sprih platform supports multi-jurisdiction disclosure.