IFRS S1/S2: Mandatory vs. Voluntary Checklist
Sustainability Reporting
Jul 8, 2025
Explore the key differences between mandatory and voluntary adoption of IFRS S1 and S2 standards for sustainability disclosures.

The IFRS S1 and S2 standards, introduced by the ISSB, aim to standardise sustainability-related financial disclosures globally. Organisations face a critical choice: adopt these standards voluntarily or comply mandatorily when required by regulators. Here's the key takeaway:
Mandatory Adoption: Enforced by regulators or stock exchanges, often tied to company size, industry, or jurisdiction. Requires immediate compliance with strict deadlines and audit-ready systems.
Voluntary Adoption: Proactively implemented to meet stakeholder expectations, improve transparency, and prepare for future regulations. Offers flexibility and phased implementation.
Key considerations include regulatory obligations, organisational readiness, stakeholder demands, and potential benefits like improved access to capital and credibility. Early adoption can provide a competitive advantage, while mandatory compliance ensures alignment with evolving legal requirements.
Quick Overview:
IFRS S1: General sustainability disclosures.
IFRS S2: Climate-specific reporting.
UK developments: FCA exploring mandatory adoption for listed companies.
Global trends: Countries like Malaysia and Australia already enforcing ISSB standards.
Organisations should assess their readiness, regulatory status, and stakeholder expectations to decide the best approach. Investing in robust systems and clear governance frameworks is essential for effective adoption.
When IFRS S1 and S2 Adoption is Mandatory
Mandatory compliance with IFRS S1 and S2 comes into play when regulatory authorities or stock exchanges enforce these sustainability disclosure standards. Organisations must act promptly to meet these requirements and avoid penalties.
Regulatory and Stock Exchange Requirements
In the UK, the regulatory framework for sustainability reporting is still taking shape. The Financial Conduct Authority (FCA) is working on proposals that would require listed companies to adopt UK Sustainability Reporting Standards (SRS) under its listing rules. This marks a significant move towards mandatory sustainability disclosures for publicly traded firms.
Currently, organisations must adhere to existing climate-related disclosure rules that align with IFRS S1 and S2. For instance, under FCA listing rules, premium and standard listed companies are required to include climate-related financial disclosures in their annual reports, following the recommendations of the Task Force on Climate-Related Financial Disclosures (TCFD). Additionally, the FCA's ESG Sourcebook mandates annual TCFD entity reports from asset managers, life insurers, and FCA-regulated pension providers.
The UK government is exploring ways to expand on these climate-related obligations to establish a more robust framework for sustainability-related financial disclosures. New reporting requirements from the FCA could be introduced sooner, while changes made through the Companies Act 2006 would depend on future legislation.
For organisations already reporting under frameworks like the Streamlined Energy and Carbon Reporting (SECR) or TCFD, transitioning to mandatory IFRS S1 and S2 compliance is relatively straightforward. These companies are better equipped to adapt as the reporting standards evolve.
Next, let’s explore how company size and thresholds influence these requirements.
Size and Threshold Requirements
In many cases, company size determines whether mandatory adoption applies. The UK government is considering legislation under the Companies Act 2006 to introduce mandatory reporting for large companies. While global practices offer useful insights, UK-specific thresholds are still under review.
Malaysia provides a clear example with its National Sustainability Reporting Framework (NSRF), which enforces ISSB standards for all listed companies on Bursa Malaysia’s main and ACE markets, as well as for large non-listed companies with annual turnover exceeding RM 2 billion. This demonstrates a size-based approach to mandatory adoption.
Similarly, Australia has introduced legislation for ISSB-aligned reporting requirements, with a phased implementation. Large listed and private entities that meet specific thresholds for revenue, assets, employees, or emissions must disclose climate-related information. Assurance requirements will also be introduced gradually, with full disclosure expected to meet reasonable assurance standards by FY2030.
Industry-Specific Requirements
Certain industries, particularly those with significant environmental impacts, are more likely to face mandatory adoption earlier. IFRS S1 specifically requires industry-focused disclosures, using SASB standards as a guide for identifying sustainability-related risks and opportunities. Industry-specific disclosures are particularly valuable because the effects of sustainability issues vary across sectors.
Sectors such as energy, mining, manufacturing, and financial services often face earlier adoption deadlines due to their substantial environmental footprints and exposure to climate-related risks. Companies in these industries should consult SASB standards to understand their disclosure obligations.
The ISSB’s standards have gained strong international backing, supported by the G7, G20, the International Organisation of Securities Commissions (IOSCO), and the Financial Stability Board. This global momentum underscores the growing regulatory push towards mandatory adoption.
For organisations looking to integrate ISSB reporting into their financial strategies, it’s crucial to stay updated on announcements from local regulators regarding IFRS S1 and S2 adoption timelines. In the UK, the timing of mandatory implementation will depend on future legislative developments.
These considerations lay the groundwork for a detailed checklist to guide decision-making.
When to Choose Voluntary Adoption
While some organisations face regulatory requirements, others choose to adopt IFRS S1 and S2 voluntarily to gain an edge in the market. By doing so, they not only prepare for potential future regulations but also position themselves strategically.
Stakeholder Expectations
Today's stakeholders, especially investors, increasingly expect companies to provide clear, comparable sustainability data. Reliable sustainability reporting helps investors make better decisions about capital allocation. By adopting these standards voluntarily, organisations can enhance transparency and build trust, making themselves more appealing to investors who prioritise environmental, social, and governance (ESG) factors.
This shift in expectations highlights a broader trend: sustainability reporting is moving from optional corporate social responsibility (CSR) disclosures to mandatory, investor-focused frameworks. Meeting these rising demands early can offer organisations a distinct advantage.
Benefits of Early Adoption
Adopting IFRS S1 and S2 early can help organisations avoid the rush to comply when regulations eventually become mandatory. For example, Brazil has already integrated these standards into its regulatory framework, setting a precedent other countries may follow. Early adoption ensures organisations are prepared for such transitions without last-minute challenges.
Beyond compliance, early adoption can enhance a company's reputation and market position. Organisations that embrace these standards early can use ESG data to make informed decisions, attract investment, and build stronger relationships with stakeholders. For those aiming to integrate sustainability into their financial strategies, understanding how ISSB reporting aligns with these goals can unlock further opportunities.
Internal Readiness Assessment
Before implementing IFRS S1 and S2, it's essential to evaluate your organisation's readiness. This involves a detailed review of several critical areas to ensure successful adoption.
Governance and strategy: Check if your current governance framework supports sustainability reporting and whether your sustainability strategy aligns with the disclosure requirements. Address any gaps before moving forward.
Data quality and processes: Reliable data is the backbone of sustainability reporting. Ensure you have robust systems in place to collect and analyse high-quality data that aligns with IFRS standards.
Understanding the standards: It's crucial for your team to fully grasp the requirements of IFRS S1 and S2. This understanding should extend beyond the sustainability team to include finance, operations, and leadership.
Organisation-wide education: Build awareness across all departments about the importance of sustainability reporting and how each team contributes to the process.
Sustainability roadmap: Develop a clear plan outlining how you’ll address gaps, set milestones, and assign responsibilities. Be realistic about potential constraints, such as budget or resource limitations.
Many organisations find that after completing this readiness assessment, voluntary adoption is more achievable than initially thought - especially if they already have experience with sustainability reporting or strong data management systems in place.
Decision-Making Checklist
Choosing between mandatory and voluntary adoption of sustainability standards requires careful analysis of your organisation's unique situation. This checklist offers a step-by-step guide to help you make an informed decision.
Evaluation Steps
Verify your regulatory status. Check whether your jurisdiction or industry imposes mandatory requirements. As of September 2024, 30 countries were moving towards legal adoption of these standards. Nations like the United Kingdom, Japan, Canada, and Australia have already indicated plans to include them in their reporting frameworks. Consult your regulatory body or legal counsel to confirm your obligations.
Assess size and threshold criteria. Many jurisdictions base mandatory adoption on factors like revenue, employee numbers, or market value. Determine if your organisation meets these benchmarks or is likely to do so soon.
Engage key stakeholders. Survey your major investors, lenders, and business partners to understand their sustainability reporting expectations. Many stakeholders now prefer or require IFRS-compliant disclosures for decision-making.
Perform a cost-benefit analysis. Calculate the costs of implementation, including technology upgrades, training, and consultancy fees. Balance these against potential benefits like better access to funding, enhanced reputation, and stronger stakeholder relationships. Don’t overlook the risks of not adopting, such as losing competitive ground or missing investment opportunities.
Conduct a materiality assessment. Identify how sustainability risks and opportunities could impact your financial performance and funding. This will help you decide whether these standards align with your business model and stakeholder priorities.
Review compatibility with existing frameworks. If your organisation already uses frameworks like GRI, SASB, or TCFD, evaluate how IFRS S1 and S2 fit into your current reporting processes. Proper alignment can simplify implementation and reduce costs.
Once your organisational evaluation is complete, ensure your technology systems are equipped to handle the required data processes.
Technology Requirements
After assessing your organisation, focus on technology readiness. A reliable technological infrastructure is critical for implementing IFRS S1 and S2 effectively. These standards demand systems that can collect, process, and report ESG data with precision.
Seamless integration with existing systems. Your platform should work smoothly with tools like accounting software, ERP systems, energy metres, and HR systems. This ensures data accuracy and minimises manual input errors.
Automation capabilities. Managing ESG data can be complex and time-consuming. Choose platforms with AI-powered data collection and reporting features to streamline processes and reduce errors.
Support for multiple frameworks. If you report under various standards, such as ISSB (IFRS S1 & S2), CSRD, or GHGP, opt for a platform that accommodates all these requirements. This flexibility allows you to manage diverse reporting obligations in one place.
For a comprehensive solution, platforms like neoeco are tailored for IFRS S1 and S2 compliance. The neoeco platform’s FiS Ledger integrates over 90 ESG impact factors into financial transactions using double-entry principles, delivering audit-grade accuracy while meeting ISSB reporting requirements.
Audit-ready reporting. Ensure your technology can produce reports that meet the stringent standards of auditors and regulators. Features like clear audit trails, robust documentation, and standardised report formats are essential.
Internal expertise and usability. Evaluate the technical skills required to implement and maintain the platform. Some systems are complex, while others offer user-friendly interfaces that finance and sustainability teams can manage independently.
Ongoing support and scalability. Budget for training and ongoing support, as even intuitive platforms may require initial guidance. Additionally, ensure your chosen system can scale with evolving reporting needs without requiring a complete overhaul.
Mandatory vs Voluntary: Side-by-Side Comparison
Expanding on the earlier discussion of regulatory requirements and voluntary approaches, this section breaks down the key differences between the two. Understanding these trade-offs is crucial for shaping your sustainability reporting strategy. Each path has distinct benefits that influence timelines, resource needs, and overall implementation.
Comparison Table
Aspect | Mandatory Adoption | Voluntary Adoption |
---|---|---|
Compliance Drivers | Legal mandates, regulatory deadlines, and stock exchange requirements | Stakeholder expectations, competitive edge, and investor interest |
Implementation Timeline | Fixed deadlines (starting 1 January 2024 for applicable periods) | Flexible, phased implementation that allows gradual development |
Resource Requirements | Requires significant upfront investment in systems and expertise to meet tight deadlines | Allows for progressive investment, building systems over time |
Data Quality Standards | Must meet audit-ready standards from the outset | Can start with "reasonable and supportable" data, especially for first-time reporters |
Transparency Benefits | Enhances transparency and comparability, aiding better stakeholder decisions | May lack the consistency and comparability of mandatory frameworks |
Risk Management | Supports the identification and management of sustainability risks, improving resilience | Offers a learning curve to adapt before regulations are enforced |
Reputation Impact | Boosts credibility and signals strong commitment to sustainability | Attracts investors focused on sustainability, offering a competitive edge |
Operational Flexibility | Limited flexibility due to strict regulatory requirements | High flexibility to tailor standards to existing processes and business needs |
Cost Considerations | Higher initial costs driven by compliance deadlines | Lower upfront costs, with phased implementation using qualitative methods |
Future-Proofing | Aligns with evolving regulatory standards and prepares for future mandates | Positions businesses ahead of regulatory changes while maintaining adaptability |
This comparison underscores the differences between mandatory and voluntary approaches, helping organisations navigate their decision-making process. The choice often hinges on the regulatory environment. With IOSCO endorsing these standards across 130 member jurisdictions, voluntary adoption today could become mandatory in the near future. Many regions are already signalling a transition toward mandatory frameworks.
The financial implications of each approach also differ. Mandatory adoption typically demands a significant initial outlay to comply with strict deadlines, whereas voluntary adoption allows for gradual capability building. To ease the burden, the ISSB has introduced transition reliefs and proportionality measures, addressing readiness levels and reducing costs. For context, large multinational companies face estimated costs of 0.004–0.008% of revenue for comprehensive sustainability reporting.
While mandatory adoption requires systems to be audit-ready from the start, voluntary adoption offers more flexibility. Companies can initially rely on qualitative methods when quantitative data is hard to obtain, a practical option for organisations with limited resources or those new to sustainability reporting.
Platforms like neoeco's ISSB reporting can support both approaches, helping businesses meet current and future compliance requirements.
Voluntary adoption also offers a timing advantage. Since 2020, 2,839 companies have disclosed sustainability information using SASB standards, showing significant momentum ahead of regulatory mandates. Companies already using SASB standards will find it easier to adapt to IFRS S1 and S2 requirements, making voluntary adoption an appealing choice for those with established frameworks.
Finally, stakeholder expectations are increasingly driving the push for consistent and comparable disclosures, regardless of regulatory mandates. Investors rely on these standards to guide decisions and monitor portfolio performance, creating market pressure that often surpasses formal requirements. This makes voluntary adoption not just a compliance option but a strategic move for forward-thinking organisations.
Next Steps
Choosing between mandatory and voluntary adoption of IFRS S1 and S2 will depend on your organisation’s specific circumstances, including its regulatory environment and strategic goals. Key aspects to consider include jurisdictional requirements, stock exchange obligations, company size, industry-specific rules, stakeholder demands, and your organisation’s readiness to comply.
Start by performing a gap analysis of your current governance structure and sustainability strategy. This process will help you pinpoint areas that need improvement to align with IFRS S1 and S2 requirements. Pay close attention to your data collection capabilities, internal controls, and reporting mechanisms - these are the backbone of effective sustainability disclosures.
Use the results of your gap analysis to craft a focused sustainability roadmap. This plan should include clear milestones, assigned responsibilities, and an understanding of potential constraints. Keep in mind that sustainability reports must be filed alongside financial statements, making it essential to coordinate timelines effectively.
It’s often practical to begin with IFRS S2 climate disclosures, as these address the most pressing sustainability risks. If your organisation is among the 2,839 companies already using SASB standards as of August 2023, frameworks like TCFD and SASB can serve as a strong foundation.
Technology infrastructure is another critical factor. Evaluate whether your current systems can handle the data collection, analysis, and reporting demands of IFRS S1 and S2. An integrated solution can simplify processes and minimise manual errors by leveraging automation.
Building on this, platforms like neoeco offer tools to support comprehensive ISSB reporting. These platforms use AI-driven automation and accommodate multiple standards, including IFRS S1 and S2, helping organisations bridge the gap between financial and sustainability data - whether for mandatory or voluntary adoption.
Education is equally important. Ensure that employees at all levels understand not just the technical requirements but also how sustainability aligns with your organisation’s broader strategy and financial goals. This knowledge will enhance implementation efforts and enable your team to effectively communicate your sustainability narrative to consumers and investors alike.
The regulatory landscape is shifting rapidly, with countries like the United Kingdom, Japan, Canada, and Australia moving towards incorporating these standards into mandatory reporting frameworks. Preparing early, whether through mandatory compliance or voluntary adoption, can offer a strategic advantage in this evolving environment.
FAQs
What are the key advantages of adopting IFRS S1 and S2 standards before they become mandatory?
Voluntarily implementing IFRS S1 and S2 standards before they become mandatory can bring a range of advantages. For starters, it boosts transparency in sustainability reporting, which helps build trust with investors and other stakeholders. This improved clarity can also make it easier to secure funding by showcasing your organisation’s commitment to accountability.
Getting ahead of the curve means your organisation has time to fine-tune its reporting processes, minimising the risk of compliance issues down the line. Beyond that, early adoption can position your company as a front-runner in sustainability efforts, giving you a competitive advantage and making your business more appealing to investors. It also signals a strong dedication to sound governance and strategic planning - qualities that can lay the groundwork for long-term stability and growth.
How do a company’s size and industry affect whether IFRS S1 and S2 adoption is mandatory or voluntary?
IFRS S1 and S2: Who Needs to Comply?
IFRS S1 applies to all organisations that report under IFRS, no matter their size or industry. It's a universal requirement, leaving no room for exceptions.
However, the story is different for IFRS S2. Whether a company must comply depends largely on local regulations. Larger corporations, especially those in industries like energy or finance where regulation is stricter and the environmental impact is significant, are more likely to face mandatory adoption sooner. On the other hand, smaller businesses or those in less regulated sectors might adopt IFRS S2 voluntarily or may not be required to comply right away.
The timing of mandatory adoption hinges on the policies of individual jurisdictions. Some countries enforce stricter or earlier deadlines, while others may take a more gradual approach. For organisations, this means it's crucial to evaluate their regulatory landscape and align their ESG strategies to decide the most effective way to implement these standards.
How can organisations evaluate their readiness to adopt IFRS S1 and S2 standards?
Preparing for IFRS S1 and S2 Adoption
Getting ready to adopt IFRS S1 and S2 begins with identifying the sustainability-related risks and opportunities that are most relevant to your organisation. This means examining how these factors influence your strategy, governance, and overall financial performance.
The next step is to take a close look at your current data collection methods, reporting processes, and governance structures. Make sure they align with the standards' requirements, which include disclosures on governance, strategy, risk management, and key metrics. Incorporating scenario analyses and climate resilience testing can help uncover gaps and highlight areas that need improvement.
Platforms like neoeco, a Financially-integrated Sustainability Management (FiSM) tool, can simplify this transition. By automating data collection and offering real-time insights, neoeco supports audit-ready ESG disclosures. This not only ensures compliance with global standards but also strengthens your organisation's ESG strategy with greater transparency and efficiency.
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