First IFRS S1 and S2 Reporting Cycle: A 12-Month Implementation Plan

Technical note. This article distinguishes IFRS requirements from London Reporting Academy implementation practices. Illustrative examples and tools must be adapted to the entity’s facts, reporting period, jurisdiction and applicable adoption requirements.

Independence note. London Reporting Academy is an independent education and consulting provider. IFRS®, ISSB®, IFRS S1 and IFRS S2 are referenced for educational purposes; this material is not issued or endorsed by the IFRS Foundation.

A first IFRS S1/S2 report is not created by writing four narrative sections and adding a greenhouse gas table. The publication depends on a chain of decisions: what standards and reliefs apply; which sustainability-related risks and opportunities could affect the entity’s prospects; what information is material; how the conclusions connect to strategy and financial planning; which metrics, estimates and controls are needed; and whether the final package supports the proposed reporting claim.

The 12-month sequence below is deliberately front-loaded. Scope, governance, source review and data architecture start before detailed drafting because they determine what the report will need to say. Climate scenario analysis, financial effects, Scope 3 data and industry metrics often have longer lead times than narrative drafting. A dry run before year end exposes weak definitions, missing evidence and unreconciled assumptions while there is still time to remediate them.

Twelve months is an illustrative planning horizon, not an IFRS requirement. A mature entity may compress some stages; a complex group may need longer. The important discipline is the order of dependencies and the presence of review gates. If the project starts later, management should explicitly decide which work can be accelerated, which information will rely on estimates or reliefs, and which reporting claim remains supportable.

Figure 1. First IFRS S1/S2 reporting cycle: an illustrative 12-month roadmap with practical outputs and control gates.

Start with a signed basis-of-preparation paper. It should identify the reporting entity, annual reporting period, proposed location, intended publication timing, applicable IFRS S1 and IFRS S2 editions, jurisdictional adoption basis, transition reliefs under consideration, intended compliance or alignment claim, and the relationship to the financial statements. The project should not rely on the report title or a generic “ISSB-aligned” objective to answer these questions later.

Create a governance map covering the board or committee responsible for oversight, executive sponsor, CFO accountability, technical owners, data owners, reviewer, internal audit and any assurance practitioner. Approve the programme charter, RACI, issue-escalation thresholds, source hierarchy, documentation standards and final decision rights. Agree the time-horizon definitions or a method for linking them to strategic and capital-allocation horizons.

Identify the sustainability-related risks and opportunities that could reasonably be expected to affect the entity’s prospects. The exercise should use reasonable and supportable information available without undue cost or effort and apply the IFRS S1 source hierarchy. Where no specific IFRS Sustainability Disclosure Standard applies, the entity is required to refer to and consider the applicability of the SASB Standards. Other permitted sources may be considered without overriding IFRS requirements.

Work across industries, business units, geographies, products, operations, financing relationships and the value chain. Link the exercise to enterprise risk management but do not assume that the existing risk register is complete for disclosure purposes. Record the source, description, affected part of the business model or value chain, potential financial transmission channel, time horizon and responsible owner for each candidate item.

Apply materiality to the information about the identified risks and opportunities. The decision is entity-specific and focuses on whether omission, misstatement or obscuring could reasonably be expected to influence primary users’ decisions. The team should document significant judgements, aggregation and disaggregation decisions, and why excluded information is not material.

Translate the conclusions into a disclosure architecture. Map material items to governance, strategy, risk management, metrics and targets; identify cross-cutting requirements; assign preliminary evidence and data needs; and create the first version of the disclosure matrix. This is also the point to confirm which industry-based metrics and thematic methods require long-lead data work.

Identify climate-related physical and transition risks and opportunities, including their concentration in the business model and value chain. Define the scenario-analysis objective, time horizons, scenarios, key assumptions, inputs, methods and governance. The approach should be commensurate with the entity’s circumstances, taking account of exposure, skills, capabilities and resources.

Scenario analysis should inform the resilience assessment, not merely decorate the report. Establish which strategic questions it will test: asset vulnerability, demand shifts, input costs, supply interruption, financing, technology choices, insurance or capital allocation. Document limitations and the relationship between scenarios and the central financial forecast. If external models are used, retain enough evidence to understand the input, transformation and conclusion.

Map each material risk and opportunity to current and anticipated financial effects. Identify affected financial position, performance and cash-flow categories; investment and disposal plans; sources of funding; forecast drivers; accounting estimates and judgements; and significant uncertainty. Create an assumption bridge between sustainability analysis, scenarios, budgets, forecasts and the related financial statements.

Finance should screen the risk universe for potential implications under applicable accounting standards. The sustainability disclosures do not create new recognition or measurement rules, but inconsistent assumptions or unexplained differences can undermine connected information. Decide where quantitative information, ranges or qualitative disclosure will be used, and document the paragraph basis and evidence for any relief from quantification.

Complete the metric register. Include cross-industry climate metrics, applicable industry-based metrics, entity-specific metrics and targets. For each metric record its definition, purpose, unit, boundary, period, methodology, assumptions, estimation hierarchy, source system, owner, reviewer, control, target linkage and comparative treatment. Confirm which SASB industries apply to a diversified group and document modifications or additional metrics.

Create the evidence register and retention rules at the same time. Narrative disclosures need evidence just as much as quantitative metrics: policies, board papers, strategy decisions, risk methodologies, scenario documents, target approvals and performance reviews. Establish version control and access arrangements so the final report can be traced without relying on personal inboxes.

Complete a full dry run of Scope 1, Scope 2 and Scope 3 data before the reporting period closes. Reconcile the organisational boundary to the reporting entity and explain metric-specific differences. Screen all relevant Scope 3 categories, determine estimation methods, assess data quality, and prepare the methodology and limitation disclosures. Financial institutions should separately address Category 15 and financed-emissions requirements as applicable.

Test the December 2025 amendments to IFRS S2 against the reporting period. The amendments are mandatorily effective for annual periods beginning on or after 1 January 2027, with earlier application permitted. Early adoption or future readiness may require changes to classification systems, GWP values, jurisdictional methods, Category 15 processes, comparative data and controls. Record the decision and update the source-set version.

Translate the evidence and metric architecture into controls. At minimum, define owner sign-off, source-system extraction, access control, calculation review, reconciliations, change control, model governance, segregation of preparation and review, judgement approval, cross-report consistency, legal review, completeness testing and management representation. Control design should be proportionate to materiality and risk, but it should be capable of operating in the first reporting period.

Run a control walk-through and retain evidence. A policy or control description is not proof that the control operated. Identify exceptions, assess their effect on the disclosure and prioritise remediation. Where external assurance is planned, agree the criteria, scope, level, timetable, evidence protocol and treatment of findings early enough to avoid a last-minute discovery that key records were not retained.

Draft the entire package, including the reporting basis, cross-cutting requirements, the four pillars, climate detail, GHG methods, metrics, targets, financial effects, judgements, uncertainty, reliefs, comparatives and the proposed compliance statement. Cross-references should be tested against IFRS S1 conditions and the referenced information should be available on the same terms and at the same time.

The disclosure matrix should connect each applicable requirement to its draft location, evidence reference, owner, control, relief or judgement and reviewer status. Conduct a red-team review for unsupported claims, false precision, hidden assumptions, contradictions with the financial statements, outdated paragraph references and wording that treats illustrative practice as an IFRS requirement.

Freeze methodologies and close the period data under controlled cut-off rules. Complete GHG calculations, metric performance, target progress, current financial effects, anticipated-effects updates and comparative information where required. Reconcile published numbers to source systems and the related financial statements, and document legitimate differences in boundary, method, time horizon or scenario.

Operate a late-adjustment protocol. Every change after hard close should identify the affected disclosure, calculation, evidence, control, comparative, cross-reference and approval. Repeat the materiality and completeness assessment for significant subsequent information. This discipline prevents a late narrative improvement from creating a technical inconsistency.

Complete internal audit, technical review, legal review and external assurance procedures within their agreed scopes. Resolve findings or document their effect. Prepare the board pack: reporting basis, material risks and opportunities, financial connectivity, scenario analysis, GHG and metrics, reliefs, judgements, control exceptions, assurance scope, unresolved matters and the proposed compliance conclusion.

The board or designated approver should authorise the package only after it understands what is complete, what is estimated, what reliefs were used and what changes remain delegated. If one applicable material requirement is not met, the entity should not use an explicit and unreserved statement of compliance. A transparent alternative claim may still be possible, but it must accurately describe the basis of preparation.

Publish the disclosures in the required location and at the required time. IFRS S1 generally requires publication at the same time as the related financial statements and for the same reporting period, subject to the first-year transition relief in paragraph E4. Confirm accessibility of cross-referenced information, final version control, approvals, source links, digital tagging requirements where applicable and the relationship to other reports.

Archive the controlled package: final disclosures, evidence register, calculation files, source-set version, disclosure matrix, sign-offs, board papers, assurance report, issue log and changelog. Hold a post-implementation review while decisions are fresh. Convert unresolved limitations into the next-year roadmap, establish update triggers and begin the second cycle before the first report becomes a static publication.

Figure 2. Critical path to first IFRS S1/S2 publication. Delays in scope, risk identification, financial effects or controls usually propagate to drafting and approval.

Not every task must wait for the previous month to finish. GHG data, industry metrics, scenario analysis, finance integration and control design should run in parallel once their scope is sufficiently stable. The critical path consists of decisions that change the content or claim of the whole package. Delays in these decisions are more dangerous than delays in individual drafting tasks.

Transition reliefs are optional and conditional. They should be evaluated against the entity’s reporting objective, jurisdictional rules, data readiness and future comparative burden. Use of a relief should be disclosed where required and tracked so that temporary arrangements do not become hidden permanent gaps.

The programme sponsor reorders the work. Month 1 locks the group boundary, reporting claim and transition decisions. Months 2 and 3 identify risks across manufacturing, packaging, agricultural inputs, retailers and consumer use, then determine material information. The group finds that water stress, commodity availability and packaging regulation require data and financial analysis beyond climate. A climate-only first-year relief is considered but rejected because the jurisdictional timetable and investor expectations favour a full pilot, while the compliance claim is deferred until the matrix is complete.

Scope 3 and commodity scenario work begin in parallel. By Month 7, the dry run reveals that purchased-goods estimates are highly dependent on supplier classification and that the climate narrative overstates the funding status of packaging investments. These issues are remediated before hard close. The first report is shorter than the original draft, but its boundaries, estimates, financial links and limitations are clearer and its evidence trail is substantially stronger.

Is 12 months required by IFRS S1 or IFRS S2?

No. The Standards prescribe reporting requirements, not an implementation duration. The roadmap is an LRA planning model that should be adapted to complexity, maturity, reporting date and jurisdiction.

Can a first-time reporter publish after the financial statements?

IFRS S1 paragraph E4 provides a specified first-year timing relief. The exact date depends on whether the entity is required to or voluntarily publishes an interim report. Jurisdictional rules and the intended claim must also be checked.

Can the first year cover only climate?

IFRS S1 paragraphs E5-E6 permit a climate-first transition approach in the first annual reporting period, with related comparative relief. Use must be disclosed, and the entity should plan how non-climate risks and opportunities will be added.

When should external assurance be involved?

Where assurance is required or planned, involve the practitioner early enough to agree criteria, scope, evidence and timetable. IFRS S1/S2 themselves do not impose a universal assurance requirement.

What is the most common critical-path risk?

It varies, but late decisions on reporting basis, risk and materiality scope, financial effects, Scope 3 methodology or controls often propagate into drafting and board approval.