IFRS S1 General Sustainability Disclosures — The Definitive Reference
IFRS S1, issued by the International Sustainability Standards Board in June 2023, is the foundational standard of the IFRS Sustainability Disclosure Standards. It does not prescribe metrics for any single topic. Instead it sets the framework — what counts as material, how disclosures are structured across governance, strategy, risk management and metrics and targets, where and when they are reported, and which sources of guidance a company must consult when no topic-specific standard yet exists. Every present and future ISSB topic standard, including IFRS S2 on climate, is applied through S1.
S1 is the grammar of ISSB reporting; S2 and everything that follows are sentences written in it.
IFRS S1 is the ISSB’s general standard requiring companies to disclose all material sustainability-related risks and opportunities affecting their prospects, structured across four pillars — governance, strategy, risk management, and metrics and targets. It is applied together with IFRS S2 and uses single (financial) materiality.
S1 Is the Foundation, Not a Topic Standard
The single most important thing to understand about IFRS S1 is that it is deliberately topic-agnostic. It contains no emission factors, no water-intensity metrics, no biodiversity thresholds. What it contains is the conceptual and procedural framework that all sustainability-related financial disclosures must follow, regardless of subject. A company applies S1 to establish how it identifies, assesses and reports any sustainability matter; it then applies a topic standard — currently only IFRS S2 on climate — to learn what specific information that topic demands.
- Defines materiality and the scope of risks/opportunities to report
- Establishes the four-pillar disclosure architecture
- Sets the sources-of-guidance hierarchy for topics with no standard yet
- Governs location, timing, comparatives, connected information
- Provides proportionality reliefs and first-year transition reliefs
- Applies across every present and future ISSB topic standard
- Climate-specific governance, strategy, risk and metrics requirements
- Scope 1, 2 and 3 greenhouse-gas emissions disclosure
- Climate scenario analysis and resilience
- Industry-based metrics derived from SASB Standards
- Cannot be applied alone — must be applied with S1
- The first, and so far only, ISSB topic standard
The two standards were issued together in June 2023 and are designed to be applied jointly. A company cannot apply S2 without S1, because S1 supplies the materiality definition, the connected-information requirement, the reporting-entity and timing rules, and the guidance on estimates and errors that S2 depends on. The relationship mirrors the way IAS 1 / IFRS 18 sets presentation requirements that every individual financial-reporting standard relies on.
The ISSB’s stated intent is to build a global baseline of investor-focused sustainability reporting that jurisdictions can adopt and build on. A general standard makes that baseline extensible: as the ISSB issues future topic standards (biodiversity, human capital and others are on its agenda), each one slots into the S1 framework without re-litigating materiality, presentation or timing. S1 is the load-bearing structure; topic standards are added rooms.
Historical Context — The ISSB Consolidation
IFRS S1 is the product of a deliberate consolidation of a fragmented voluntary-reporting landscape. Before the ISSB, a company wanting to report sustainability information to investors faced an alphabet soup of overlapping frameworks — TCFD, SASB, CDSB, the Integrated Reporting Framework, and others — none of which carried the authority of a single global standard-setter. The IFRS Foundation created the ISSB at COP26 in 2021 to consolidate these into one investor-focused baseline, absorbing several of the predecessor bodies.
| Year | Milestone | Significance |
|---|---|---|
| 2015 | TCFD established by the Financial Stability Board | Defines the four pillars — governance, strategy, risk management, metrics and targets — that S1 later inherits. |
| 2021 | ISSB created at COP26; VRF and CDSB consolidated into the IFRS Foundation | SASB Standards and the Integrated Reporting Framework brought under ISSB stewardship. |
| 2022 | Exposure drafts of S1 and S2 published for consultation | Global stakeholder feedback shapes the final standards. |
| June 2023 | IFRS S1 and IFRS S2 issued | First ISSB standards; general requirements (S1) plus first topic standard (S2). |
| 2024 | TCFD monitoring responsibilities transfer to the ISSB; S1/S2 effective | TCFD framework effectively succeeded by IFRS S2; S1/S2 effective for periods from 1 Jan 2024. |
| 2024–2026 | Jurisdictional adoption accelerates | Australia, the UK, Singapore, Canada, Brazil and others adopt or align; ~21 jurisdictions adopting as of January 2026. |
The consolidation matters for interpretation: because S1 absorbed TCFD’s structure and references SASB’s industry metrics, an organisation already reporting under TCFD finds the transition to S1/S2 structurally familiar rather than a rebuild. IFRS S1 itself was issued in June 2023 and is effective for annual reporting periods beginning on or after 1 January 2024, with earlier application permitted provided IFRS S2 is applied at the same time.
Objective, Scope and the Definition of Materiality
The objective of IFRS S1 is to require an entity to disclose information about its sustainability-related risks and opportunities that is useful to the users of general purpose financial reports in making decisions about providing resources to the entity. The scope is defined by effect, not by topic: an entity must disclose information about all sustainability-related risks and opportunities that could reasonably be expected to affect its cash flows, its access to finance, or its cost of capital over the short, medium or long term — collectively, the matters that could affect the entity’s prospects.
The materiality threshold is the pivot on which the whole standard turns, and it is where S1 differs most sharply from the EU regime. S1 uses the IASB’s existing definition: information is material if omitting, misstating or obscuring it could reasonably be expected to influence decisions that primary users of general purpose financial reports make on the basis of those reports. This is single — financial, or “investor” — materiality. It asks only whether a sustainability matter is financially material to the entity. It does not ask whether the entity’s activities are material to the environment or society.
| Dimension | IFRS S1 — single/financial | CSRD / ESRS — double | GRI — impact |
|---|---|---|---|
| Core question | Does the matter affect the entity’s prospects? | Both: does it affect the entity AND does the entity affect people/planet? | Does the entity affect people/planet? |
| Primary audience | Investors and capital providers | Investors plus broader stakeholders | Broad stakeholders |
| Direction | Outside-in (world → entity value) | Outside-in and inside-out | Inside-out (entity → world) |
| Reference definition | IASB materiality definition | ESRS double-materiality assessment | GRI impact-materiality |
Organisations reporting under both CSRD/ESRS and IFRS S1 cannot assume one materiality assessment satisfies both. ESRS applies double materiality — a matter is reportable if it is financially material to the entity or the entity’s impact on it is material, independently. S1 reports only the financially material subset. A topic that is material under ESRS on impact grounds (the entity’s emissions harming the climate) but not financially material to the entity may be required under ESRS and not under S1. Mapping the two requires assessing each axis separately, not assuming overlap.
The Four-Pillar Content Architecture
IFRS S1 organises every sustainability disclosure into four content areas, inherited directly from the TCFD recommendations and applied identically across S1 and all topic standards. The consistency is deliberate: a reader can navigate any ISSB disclosure — climate today, biodiversity tomorrow — using the same four-part map.
| Pillar | What it requires the entity to disclose |
|---|---|
| Governance | The governance processes, controls and procedures the entity uses to monitor, manage and oversee sustainability-related risks and opportunities — including the board/committee responsible and how management’s role is structured. |
| Strategy | The entity’s approach to managing sustainability-related risks and opportunities: the risks/opportunities themselves, their effects on the business model and value chain, their financial effects on the financial position and performance, and the resilience of the strategy. |
| Risk management | The processes the entity uses to identify, assess, prioritise and monitor sustainability-related risks and opportunities, and how those processes are integrated into overall risk management. |
| Metrics and targets | The metrics and targets the entity uses to measure and manage its performance against material sustainability-related risks and opportunities, including progress against any targets and metrics required by an applicable topic standard. |
Strategy — the pillar that carries the financial bridge
Of the four pillars, strategy does the heaviest lifting, because it is where sustainability connects to financial outcomes. S1 requires an entity to disclose not only its sustainability-related risks and opportunities but the current and anticipated effects of those matters on its business model and value chain, and — critically — the effects on its financial position, financial performance and cash flows over the short, medium and long term. This is the requirement that forces sustainability reporting out of a standalone narrative and into the same analytical frame as the financial statements.
Where in the business model and across the value chain the risks and opportunities are concentrated — not only the entity’s own operations.
Current and anticipated effects on financial position, financial performance and cash flows, over short, medium and long term — quantitative where possible, qualitative where not.
How resilient the entity’s strategy and business model are to sustainability-related risks, including the entity’s capacity to adjust.
The Sources-of-Guidance Hierarchy
The most distinctive — and most under-explained — feature of IFRS S1 is how it tells an entity to handle a sustainability topic for which no ISSB topic standard yet exists. Climate has S2. Water, biodiversity, human capital, supply-chain labour and dozens of other topics do not yet have a dedicated standard. S1 does not let an entity ignore a financially material topic merely because the ISSB has not issued a standard for it. Instead it sets a hierarchy of sources the entity must consult.
If an ISSB topic standard addresses the matter, the entity applies it. Today this means IFRS S2 for climate. As the ISSB issues further topic standards, they take first priority for their topics.
Where no ISSB standard covers the topic, the entity is required to refer to and consider the applicability of the disclosure topics and metrics in the industry-based SASB Standards. The 77 industry-specific SASB Standards are the primary source the ISSB points to for non-climate topics, and S2’s own industry metrics are themselves derived from SASB.
The entity may consider the CDSB Framework Application Guidance for water-related and biodiversity-related disclosures, where relevant, as a further source.
The entity may also consider the most recent pronouncements of other standard-setting bodies whose requirements are designed for investors — and the disclosures of entities in the same industry — to the extent these do not conflict with IFRS Sustainability Disclosure Standards. The GRI Standards and the EU ESRS are named examples of sources that may be considered at this level where non-conflicting.
In practice, most of an entity’s S1 work beyond climate happens inside this cascade. The standard is engineered so that a financially material non-climate risk — water stress at a beverage producer, labour practices in an apparel supply chain — cannot be left out simply because the ISSB has not written a standard for it. The entity works down the hierarchy until it has identified appropriate disclosure topics and metrics. Documenting which sources were consulted is itself a S1 requirement: an entity must identify the judgments it made, including the sources of guidance it used.
Core Foundational Requirements
Beyond the four pillars and the guidance cascade, S1 sets a set of cross-cutting requirements that apply to every disclosure under any ISSB standard. These are the rules that give ISSB reporting its “financial-statement-grade” character.
Disclosures must faithfully represent the sustainability-related risks and opportunities — complete, neutral and accurate, with comparable, verifiable, timely and understandable information.
Disclosures must be connected — across sustainability topics, between the four pillars, and crucially with the financial statements. Data and assumptions used in sustainability disclosures must be consistent with the corresponding financial-statement data and assumptions.
Sustainability disclosures must cover the same reporting entity as the related financial statements, so investors can read the two together without boundary mismatches.
Comparative information for prior periods is required for all amounts disclosed in the current period (subject to first-year transition relief), enabling trend analysis.
The entity must disclose the judgments it made, the sources of estimation uncertainty, and how it handled changes in estimates and prior-period errors.
An entity complying with all relevant requirements makes an explicit and unreserved statement of compliance with IFRS Sustainability Disclosure Standards.
Reporting Timing and Location
S1 ties sustainability disclosures tightly to the financial-reporting cycle. The intent is that an investor reads sustainability and financial information as a single connected package, not as two reports published months apart with different boundaries.
| Requirement | Rule |
|---|---|
| Location | Disclosures are provided as part of the entity’s general purpose financial reports. Cross-referencing to information elsewhere (e.g. a management commentary) is permitted within defined conditions. |
| Timing | Sustainability disclosures are reported at the same time as the related financial statements, covering the same reporting period. |
| Reporting entity | The same entity as the financial statements — consolidation boundary aligned. |
| First-year relief | In the first annual reporting period, an entity may report its sustainability disclosures after its financial statements (with its interim or annual report), rather than at the same time. |
Proportionality and Reliefs
S1 is calibrated so that the obligation scales with an entity’s circumstances rather than imposing a single fixed burden. Two kinds of relief operate: ongoing proportionality mechanisms built into the standard, and time-limited transition reliefs for first-time application.
Ongoing proportionality
When identifying risks and opportunities and the information to disclose, an entity uses all reasonable and supportable information available at the reporting date without undue cost or effort, including about its value chain. The scope of value-chain information an entity must gather is bounded by this threshold.
The measurement and disclosure of certain matters may be commensurate with the skills, capabilities and resources available to the entity — a smaller entity is not held to the analytical depth of a large multinational.
An entity may omit information about a sustainability-related opportunity that is commercially sensitive, where disclosing it could seriously prejudice the entity — a narrow relief that applies to opportunities, not risks, and must itself be disclosed as having been applied.
First-year transition reliefs
In the first annual reporting period, an entity may disclose information on only climate-related risks and opportunities (applying IFRS S2), deferring other sustainability topics to the following year. Several jurisdictions have built this relief into their adoption.
In the first year, sustainability disclosures may be published after the financial statements rather than at the same time, easing the simultaneous-reporting burden during transition.
An entity is not required to disclose comparative prior-period information in its first year of applying the standards.
The transition reliefs do not reduce what S1 ultimately requires — they stagger when it lands. A company taking the climate-first relief still owes full multi-topic S1 disclosures from year two, and a company omitting a commercially sensitive opportunity must still state that it has done so. Treating the reliefs as permanent carve-outs is a common misreading that produces a year-two compliance cliff.
S1 in Relation to S2 and Future Topic Standards
The S1–S2 relationship is the clearest illustration of how the general standard governs topic standards. S2 inherits its entire architecture — the four pillars, the materiality definition, the connected-information requirement, the timing and location rules — from S1. S2 then adds the climate-specific content: the requirement to disclose Scope 1, 2 and 3 greenhouse-gas emissions measured in line with the GHG Protocol Corporate Standard, climate scenario analysis, transition-plan information, and industry-based metrics.
Materiality definition · four-pillar structure · connected information · reporting entity and timing · sources-of-guidance cascade · judgments, estimates and errors · proportionality and transition reliefs.
Scope 1/2/3 emissions disclosure · cross-industry climate metrics · climate scenario analysis and resilience · transition plans · SASB-derived industry metrics · climate targets.
Future ISSB topic standards will follow the same pattern: each will plug climate-style topic content into the unchanged S1 framework. The ISSB has signalled work on topics beyond climate, meaning the value of understanding S1 compounds — it is the part of the system that does not change as new topics arrive. For the live detail of the climate topic standard, see the dedicated IFRS S2 reference.
Worked Illustration — A Non-Climate Disclosure Under S1
The following illustration shows how S1 operates for a topic with no dedicated ISSB standard, using the sources-of-guidance cascade. It is structural, not numeric — S1 disclosures are largely qualitative.
Scenario: A beverage manufacturer identifies water stress in two sourcing regions as a sustainability matter. There is no ISSB topic standard for water.
Step 1 — Materiality: The entity assesses whether water stress could reasonably be expected to affect its prospects. Disrupted supply, capital expenditure on water security and potential cost-of-capital effects make it financially material. It is in scope.
Step 2 — Sources of guidance: No ISSB standard applies, so the entity consults the SASB Standard for its industry (Non-Alcoholic Beverages / Processed Foods, which carries water-management metrics), then the CDSB Framework Application Guidance for water, then other investor-focused sources where non-conflicting.
Step 3 — Four pillars: It discloses governance of water risk; the strategy effects on business model, value chain and the financial position; the risk-management process for identifying and monitoring water stress; and the metrics and targets (e.g. water withdrawn in high-stress areas, reduction targets) drawn from the SASB metrics.
Step 4 — Connected information and judgments: Water assumptions are reconciled with those in the financial statements, and the entity discloses the judgments it made — including that it used SASB and CDSB guidance in the absence of an ISSB water standard. The disclosure is published with, and for the same entity and period as, the financial statements.
Global Adoption and Jurisdictional Divergence
IFRS S1 is not self-executing law anywhere — it becomes mandatory only where a jurisdiction adopts or endorses it, and jurisdictions vary in scope, timing and whether they adopt the full S1 framework or begin climate-first via S2. As of January 2026, around 21 jurisdictions had adopted the ISSB standards on a voluntary or mandatory basis, with many more announcing intentions to align, representing a large share of global market capitalisation.
| Jurisdiction | Approach | Notes |
|---|---|---|
| Australia | AASB S1 (voluntary) + AASB S2 (mandatory) | Climate reporting mandatory for periods from 1 Jan 2025, phased by entity size; see AASB S2. |
| United Kingdom | UK Sustainability Reporting Standards (UK SRS), ISSB-based | UK-endorsed standards developed from S1/S2; FCA rules for listed companies under consultation; builds on existing UK TCFD-aligned disclosure. |
| Singapore | SGX/ACRA ISSB adoption, climate-first | Phased by issuer class; climate-first basis (IFRS S2), with broader S1 topics not yet mandated; see Singapore SGX disclosure. |
| Canada | Canadian Sustainability Disclosure Standards (CSDS 1 & 2) | ISSB-aligned standards issued by the CSSB; adoption pathway via securities regulators. |
| Brazil | CVM adoption, mandatory phase-in | ISSB standards adopted for listed companies, mandatory application from fiscal years after 1 Jan 2026. |
| Others | Chile, Qatar, Mexico and more | Rules mandating ISSB-based standards became effective at the start of 2026 in several jurisdictions; further adoptions are in progress. |
Adoption status as of early 2026 (S&P Global ISSB adoption tracker, January 2026). Jurisdictional rules change frequently; verify the current position for any specific entity before relying on it.
Several jurisdictions begin by mandating only the climate topic standard (S2) while deferring the broader multi-topic scope of S1. An entity reporting “under ISSB” in such a jurisdiction may, in its early years, be disclosing climate only — not the full breadth of financially material sustainability topics that S1 ultimately reaches. Do not read a climate-first mandate as full IFRS S1 compliance; the gap closes only as the jurisdiction extends scope.
Assurance and Connectivity to Financial Reporting
S1’s design — same reporting entity, same timing, connected assumptions, comparatives — exists to make sustainability information assurable to a standard approaching that of financial statements. Many adopting jurisdictions phase in assurance requirements, typically beginning with limited assurance and escalating over time. The connectivity requirement is what makes this possible: because sustainability data and assumptions must be consistent with the financial statements, an assurer can test them against an audited financial baseline rather than against an unanchored narrative.
The practical consequence for preparers is that sustainability reporting under S1 cannot live solely in a sustainability team. The financial-effects disclosures in the strategy pillar, the connected-information requirement, and the alignment of assumptions all force collaboration between sustainability, finance and risk functions. Organisations that treat S1 as an extension of financial reporting governance — rather than a separate ESG exercise — tend to produce more defensible, assurable disclosures.
Interoperability Matrix
S1’s stated purpose is to be a global baseline that interoperates with other frameworks. Interoperability is high but not seamless; the principal divergence is materiality.
| Framework | Relationship to IFRS S1 | Principal divergence |
|---|---|---|
| IFRS S2 | Topic standard applied through S1 | None — S2 is built on the S1 framework and applied jointly. |
| TCFD | Predecessor; four pillars inherited by S1/S2 | TCFD effectively succeeded by IFRS S2; S1/S2 are more granular and assurable. |
| CSRD / ESRS | Interoperability guidance jointly published | Double materiality (ESRS) vs single/financial materiality (S1); ESRS reaches broader stakeholder audience. |
| GRI Standards | A source that may be considered in the guidance cascade | Impact materiality and broad-stakeholder audience vs investor focus. |
| SASB Standards | Required source of guidance for non-climate topics; under ISSB stewardship | Industry-specific topics/metrics; S1 requires considering their applicability. |
| CDP | Disclosure platform aligned to ISSB | CDP’s questionnaire uses IFRS S2 as a baseline; data feeds rather than replaces S1/S2. |
Common Implementation Errors
How GreenCalculus Supports IFRS S1/S2 Disclosure
IFRS S1 is a qualitative framework, but its metrics-and-targets pillar and the climate content it carries through S2 rest on quantitative greenhouse-gas accounting. GreenCalculus provides the calculation layer beneath the disclosure layer: the emissions figures that populate S2’s Scope 1, 2 and 3 metrics, and the disclosure-readiness tooling that maps those figures into the four-pillar structure.
| Function | Status | Where it connects |
|---|---|---|
| IFRS S2 climate-disclosure tooling | Live | IFRS S2 Climate Disclosure Calculator |
| Scope 1/2/3 emissions for the metrics pillar | Live | GHG Protocol calculators feeding S2’s emissions metrics |
| Cross-framework mapping (S1/S2 ↔ CSRD) | Live | CSRD ESRS E1 Disclosure Calculator for double-materiality reconciliation |
| Scenario analysis (S2 strategy pillar) | Live | Scenario Analysis Calculator |
| S1 multi-topic disclosure mapper | Planned | Sources-of-guidance cascade tooling for non-climate topics |
Build the climate content of your IFRS S1/S2 disclosure on verified emissions data. The metrics-and-targets pillar runs on Scope 1, 2 and 3 figures — calculate them, then map them into the four-pillar structure.
Frequently Asked Questions
IFRS S1, General Requirements for Disclosure of Sustainability-related Financial Information, is the foundational standard of the IFRS Sustainability Disclosure Standards, issued by the ISSB in June 2023. It sets the general framework for disclosing all material sustainability-related risks and opportunities that could affect an entity’s prospects, structured across four pillars — governance, strategy, risk management, and metrics and targets. It is topic-agnostic and is applied together with topic standards such as IFRS S2 on climate.
IFRS S1 is the general standard — it defines materiality, the four-pillar structure, the sources-of-guidance hierarchy, and the timing, location and connected-information rules that apply to every sustainability disclosure. IFRS S2 is the first topic standard — it adds the climate-specific content, including Scope 1, 2 and 3 emissions, scenario analysis and industry metrics. S2 is built on S1 and cannot be applied alone; the two are applied jointly.
IFRS S1 uses single, or financial, materiality, aligned with the IASB’s definition: information is material if omitting, misstating or obscuring it could reasonably be expected to influence the decisions of primary users of general purpose financial reports. It asks whether a sustainability matter is financially material to the entity — not whether the entity’s activities are material to the environment or society. This differs from the CSRD/ESRS double-materiality approach, which also assesses the entity’s impact on people and the planet.
IFRS S1 was issued in June 2023 and is effective for annual reporting periods beginning on or after 1 January 2024, with earlier application permitted provided IFRS S2 is applied at the same time. However, the standard is mandatory only where a jurisdiction adopts or endorses it. Adoption is phased and varies by country; as of January 2026, around 21 jurisdictions had adopted the ISSB standards, with many more aligning.
The four content pillars, inherited from the TCFD recommendations, are governance (the processes and controls used to oversee sustainability matters), strategy (the risks and opportunities and their effects on the business model, value chain and financial position), risk management (how risks and opportunities are identified, assessed and monitored), and metrics and targets (how performance is measured and managed). All ISSB standards, including IFRS S2, use this same four-part structure.
For a financially material topic with no dedicated ISSB standard — water, biodiversity, human capital and others — S1 sets a sources-of-guidance hierarchy. The entity first applies any relevant IFRS Sustainability Disclosure Standard, then refers to and considers the applicability of the industry-based SASB Standards, then the CDSB Framework Application Guidance for water and biodiversity, and may then consider other investor-focused standard-setters and industry practice where these do not conflict with the ISSB standards. The entity must disclose which sources of guidance it used.
In the first year of application, an entity may disclose only climate-related information (applying IFRS S2 and deferring other topics), may report its sustainability disclosures after the financial statements rather than at the same time, and is not required to provide comparative prior-period information. These reliefs are time-limited to the first year and do not reduce the standard’s ultimate requirements — they stagger when full compliance lands. There is also a narrow ongoing relief allowing omission of commercially sensitive information about opportunities.
IFRS S1 is not self-executing law on its own — it becomes mandatory only where a jurisdiction adopts or endorses it. Jurisdictions vary in scope and timing, and some begin climate-first by mandating only IFRS S2 while deferring the broader S1 scope. As of early 2026 around 21 jurisdictions had adopted the ISSB standards on a voluntary or mandatory basis, including Australia, Canada, Brazil, Singapore and others, with the UK developing ISSB-based UK Sustainability Reporting Standards. Verify the current position for any specific entity, as adoption rules change frequently.