ISSB reporting consulting for climate and sustainability disclosures investors can rely on.

What it is

What are the ISSB Standards, IFRS S1 and IFRS S2, and what are they used for?

The International Sustainability Standards Board (ISSB) was set up in November 2021 by the IFRS Foundation, the organisation behind the IFRS Accounting Standards, to give capital markets a consistent and comprehensive global baseline of sustainability disclosures. IFRS S1, General Requirements for Disclosure of Sustainability-related Financial Information, requires a company to disclose information about its sustainability-related risks and opportunities that is useful to the users of its general purpose financial reports when they decide whether to provide it with resources. IFRS S2, Climate-related Disclosures, does the same for climate-related risks and opportunities, with specific metrics that include greenhouse gas emissions. Both fully incorporate the recommendations of the Task Force on Climate-related Financial Disclosures (TCFD), and IFRS S2 incorporates industry-based disclosure requirements derived from the SASB Standards. IOSCO, the international body of securities regulators, has endorsed them.

The lens is the investor's. Information is material if omitting, misstating or obscuring it could reasonably be expected to influence the decisions of existing and potential investors, lenders and other creditors about providing resources to the company. That single, financial lens differs from GRI's focus on impacts and from the double materiality of the European ESRS, and it shapes the work: the question is how a sustainability matter could affect the company, and the answer has to sit consistently beside the financial statements. There is no ISSB certificate. What exists at the end is a set of disclosures, the process and evidence that produced them and, where your jurisdiction requires it or your board chooses it, an assurance conclusion.

Current text. IFRS S1 and IFRS S2 were issued on 26 June 2023 and are effective for annual reporting periods beginning on or after 1 January 2024; either may be applied earlier only together with the other. In December 2025 the ISSB issued Amendments to Greenhouse Gas Emissions Disclosures (Amendments to IFRS S2), effective for annual reporting periods beginning on or after 1 January 2027 with early application permitted, to reduce complexity, the risk of duplicative reporting and the cost of applying specific greenhouse gas requirements. The standards' own effective date applies when a company chooses to apply them; where a regulator or exchange requires them, its rules decide who reports, from which year, with which modifications and reliefs. The ISSB tracks each jurisdiction's approach in its profiles and snapshots, last updated on 24 September 2026.

Who it is for

Who needs to report under the ISSB Standards?

The ISSB cannot oblige anyone to report; jurisdictions and capital providers do. Nothing here is legal advice: your regulator's rules decide your obligations. Organisations come to Sterling from four starting points:

• Your regulator or exchange has introduced ISSB-based rules. Jurisdictions with ISSB profiles include Australia, Singapore, Malaysia, the Philippines, Hong Kong SAR, Japan and Qatar. The local rule decides who reports, from when and with which reliefs, and we build to that version.
• Investors, lenders or rating providers are asking. When capital providers want comparable climate information, applying the standards voluntarily gives them one investor-grade set instead of a questionnaire each.
• Your parent company or a major customer reports. A group applying IFRS S2 needs its subsidiaries' emissions, risks and targets on the same basis, and a customer counting Scope 3 emissions needs figures from its suppliers. Supplying them keeps you on the approved supplier list.
• You report under TCFD, GRI or CDP today. The TCFD structure carries straight into IFRS S2, and much GRI and CDP data can be reused, so moving before any deadline costs least.

Business benefits

How ISSB reporting supports investors, lenders and better decisions

A disclosure programme earns its cost where sustainability meets capital: an investor call about the transition, a bank's questionnaire on emissions, a board asking which climate risks could move the numbers.

• Investor conversations on your termsGovernance, strategy, risks and targets disclosed in the structure investors already use, so questions start from your disclosure rather than from a third party's estimate.
• Finance with fewer questionnairesLenders and insurers read one comparable set of climate information instead of sending separate requests, and due diligence moves faster.
• Climate risk inside the risk processPhysical and transition risks assessed with the same criteria, owners and review dates as every other enterprise risk, so the board sees them in proportion.
• Figures that survive assuranceEvery emissions figure and metric traced to a source, a method and a control, ready for limited or reasonable assurance when your jurisdiction or your board asks for it.
• A strategy tested against changeRisks, targets and transition actions discussed with the people who set the budget, so the disclosure describes decisions that were actually taken.
• One data set for every frameworkThe inventory, risks and metrics built for IFRS S2 also answer TCFD, GRI, CDP and ESRS requests, with the differences documented rather than recalculated.

Judge the programme by the share of metrics with a documented method and control, the days from year-end to a reviewable draft and the findings raised at assurance, not by the length of the report.

Requirements

What are the main IFRS S1 and IFRS S2 requirements?

IFRS S1 sets the general requirements for any sustainability-related risk or opportunity; IFRS S2 applies them to climate and adds specific metrics. Both are organised in four core content areas that build on the TCFD recommendations: governance, strategy, risk management, and metrics and targets. The table is a plain-language map; during the programme your disclosures are checked against the standards as issued, and as adopted where you report, requirement by requirement.

Reporting process

How do you report under the ISSB Standards?

The disclosures are built, operated through a reporting period and then, where required or chosen, assured. Sterling designs and builds the programme with your team; your regulator decides what is required and the assurance provider whether the disclosures pass.

1. 01
   Confirm what applies, and from when.Establish whether you report under a jurisdiction's ISSB-based rules or voluntarily, the first reporting period, the entities covered, the reliefs available and whether assurance is required.
2. 02
   Gap analysis: review current reporting against IFRS S1 and IFRS S2.The gap analysis tests existing TCFD, GRI or annual report content, the risk process, emissions data and governance records against the four core content areas and the IFRS S2 metrics, and agrees actions, owners and dates.
3. 03
   Identify and assess the risks and opportunities.Map the business model and value chain, screen the SASB topics for your industry, judge each risk and opportunity against the investor materiality test and record management's decision with the reasoning.
4. 04
   Build the inventory, the metrics and the disclosures.Complete the Scope 1, 2 and 3 inventory on the GHG Protocol basis, choose and calculate the industry metrics, set or restate targets, write the governance, strategy and risk management disclosures, and draft as the evidence accumulates.
5. 05
   Review internally, then complete any assurance engagement.An internal audit of the data trail and a management review of the draft, findings closed with evidence, then the assurance engagement where your jurisdiction requires it or your board wants it.
6. 06
   Maintain the programme and retire the reliefs.Run the data cycle on the financial calendar, add the topics and comparatives the reliefs deferred, apply amendments such as the December 2025 greenhouse gas changes, and track targets through the year.

Look at what an offer leaves behind, not at the page count: who assesses materiality, who builds the inventory, whether the Scope 3 method is disclosed and defensible, what your people will learn and where the workpapers will live. How to choose a credible ISSB provider · The certification buyer's checklist

Cost

How much does ISSB reporting cost?

The cost follows the scope your jurisdiction or your investors set, the number of entities and countries consolidated, the state of the emissions data and how much reporting already exists. Two things never vary in a Sterling proposal: every component is visible, and nothing is added later.

Timeline

How long does ISSB reporting take?

Five to nine months is a realistic range for a first programme under IFRS S2, measured to a draft ready for internal review: nearer five where a TCFD report, a working risk process and a Scope 1 and 2 inventory exist, nearer nine where a group must consolidate many entities and build Scope 3 estimates for the first time. Decisions on materiality, boundaries and methods set the pace, with data covering a full reporting period; the drafting does not.

If the first reporting period has already started, tell us on day one. We will say which data can still be captured, where disclosed estimates or a relief will be needed, and which decisions cannot wait. Anyone promising investor-grade disclosures in a fortnight, before seeing your data, is describing a template, not a programme.

Challenges

Common ISSB implementation challenges

First-time ISSB reporters tend to stall on the same five problems. Each has a practical answer.

Your engagement

What your ISSB engagement includes

One team and one all-inclusive proposal cover what investor-grade disclosures and a prepared team need: scoping, materiality, emissions and metrics, controls, documents, software, training and the review that proves it operates.

• Scope, gap analysis and implementation plan

  Applicable rules, entities, first reporting period and reliefs confirmed; every core content area and IFRS S2 metric tested against the current position; actions, owners and dates agreed before work starts.

• Materiality, emissions data and documentation

  The risk and opportunity assessment with its file, the greenhouse gas inventory and workpapers, industry metric calculations, targets and the disclosures themselves, drafted on Sterling's template sets and adapted to your business.

• Effivity ISO & GRC software

  The reporting programme runs in Effivity from the first workshop, included with the engagement at no additional cost.

• Training for everyone

  Preferential Sterling Academy course access and special pricing, including complimentary awareness training for your people as part of the engagement, plus internal auditor training for the team that will review the programme, as applicable to your standard.

• Internal audit and management review

  Conducted or facilitated as agreed, testing the data trail and the draft disclosures, with findings closed with evidence before any assurance provider starts.

• Assurance readiness and support

  Workpapers, the basis of preparation and answers to the assurance provider's requests prepared in advance, with support through the engagement until the conclusion is issued.

Any assurance conclusion remains with the independent assurance provider, and your reporting obligations with your regulator. Sterling consults; it does not give legal advice.

How we deliver

How Sterling supports your ISSB implementation

Every ISSB engagement runs on Sterling OS™, our delivery operating system: five phases, each with defined deliverables, decision owners and evidence. You decide how much of the work your team carries; the method, the software and the accountability stay constant.

1. 01
   Design™Guided implementation: your reporting lead, risk owners and data owners build the programme with Sterling's structure, templates, workshops and coaching.
2. 02
   Drive™Fully managed consulting: Sterling consultants carry the materiality assessment, the emissions inventory, the drafting and the assurance preparation with your teams.
3. 03
   Sustain™After the first report: the annual data cycle, the reliefs retired on plan, target tracking, internal audit, refreshers and new-hire training.
4. 04
   Automate™The programme in Effivity: risks and opportunities, the data inventory, emissions calculations, metrics, targets, supplier requests, audits and management review in one workspace.
5. 05
   Revise™Changes in the standards and in your business: the December 2025 amendments, your jurisdiction's own version, new industry guidance, an acquisition or a changed value chain.

Week one fixes the engagement team, the weekly working session, the deliverables and who decides what.

Often combined with

Standards organisations pair with ISSB IFRS S1 / S2

• AA1000AA1000 implementation and requirements: apply the AccountAbility Principles and SES, then prepare for AA1000AS v3 assurance by a licensed provider.
• B Corp CertificationB Corp certification made clear: the new B Lab Standards, Foundation Requirements, seven Impact Topics, the audit route and how Sterling prepares you.
• CBAMCBAM compliance and requirements explained: authorised declarant status, the 50-tonne threshold, verified embedded emissions and how Sterling helps you prepare.
• CDPCDP disclosure consulting: a complete, evidenced response on climate, forests and water, prepared with your team.
• CSDDDCSDDD compliance and requirements after Omnibus I: scoping, risk-based due diligence, complaints, monitoring and the 2029 start, delivered in one all-inclusive proposal.
• CSRD / ESRSCSRD and ESRS Sustainability reporting consulting: double materiality, ESRS disclosures and data prepared for limited assurance of your statement.