The Simplified ESRS: A Practical Guide for Mid-Market Companies

In December 2025, the European Financial Reporting Advisory Group (EFRAG) released the long-awaited simplified European Sustainability Reporting Standards (ESRS). This update represents a significant breakthrough for mid-market companies, making CSRD-aligned reporting more proportionate, achievable, and aligned with business reality. In this guide, we break down the key simplifications, explain what remains mandatory, and provide a practical roadmap for implementation.

What Changed in the December 2025 Simplified ESRS?

The original ESRS framework, while comprehensive, created significant compliance challenges for smaller companies. The simplified standards address these challenges while maintaining the integrity of sustainability reporting. Here are the major changes:

Reduced Mandatory Disclosure Points

The original ESRS included hundreds of potential data points across environmental, social, and governance areas. The simplified version significantly reduces the number of mandatory disclosures, focusing on the most material and relevant information for stakeholder decision-making.

Rather than reporting exhaustively on every conceivable metric, companies now focus on 40-50 core disclosure points per standard. This reduction dramatically simplifies data collection, analysis, and reporting without compromising reporting quality.

More Proportionate Requirements

Proportionality has been a core principle of the revision. The simplified ESRS recognizes that a manufacturing company with 300 employees has different data collection capacity than a 50,000-employee conglomerate. Key proportionality improvements include:

• Scaled data collection: Companies can use estimates and proxy data where exact measurement is unreasonably burdensome, with clear guidance on estimation methodologies.
• Simplified measurement: Energy, water, and waste calculations are streamlined, with standardized conversion factors and simplified boundaries.
• Flexible timelines: Companies can phase in complex metrics over 2-3 reporting cycles, allowing time to build measurement systems.

Phased Data Point Implementation

Rather than requiring all data points from day one, the simplified ESRS introduces a phasing approach. For the first reporting year, companies report on Tier 1 disclosure points (core, essential metrics). In year two, additional Tier 2 points become mandatory. This approach allows companies to build capability gradually.

Companies can report on additional disclosure points voluntarily, but only Tier 1 and (eventually) Tier 2 points are mandatory. This removes the expectation of completeness while maintaining standardization.

What Remains Mandatory Under Simplified ESRS?

While many requirements have been simplified, several core elements remain non-negotiable. Understanding these mandatory requirements is critical for compliance.

Double Materiality Assessment

The double materiality assessment remains the foundation of ESRS reporting. This assessment identifies which sustainability topics are material to your business in two dimensions:

• Financial materiality: Which ESG factors could impact your business's financial performance (cost increases, operational disruptions, market shifts, etc.)?
• Impact materiality: Which ESG factors could be materially impacted by your business (employment practices, supply chain emissions, environmental footprint, community impact, etc.)?

The double materiality assessment is the lynchpin of your reporting strategy. It determines which ESRS standards apply to your company, which disclosure points you must report, and how you prioritize data collection efforts. Performing a rigorous, defensible materiality assessment early in your implementation journey is essential.

Core Environmental Standards

All companies must address core environmental standards regardless of materiality:

• E1 Climate: Scope 1, 2, and 3 greenhouse gas emissions remain mandatory. However, measurement methodologies are simplified and estimation is permitted.
• E2 Pollution: Air, water, and soil pollution disclosures are now more streamlined, focusing on material pollutants and pathways of concern.
• E3 Water: Water consumption and quality disclosures, proportionate to your sector and operations.
• E4 Biodiversity: Biodiversity impacts and dependencies, now with simplified assessment methodologies for most companies.
• E5 Circular Economy: Resource use, waste, and circular economy metrics aligned with your business model.

Core Social Standards

All companies must address at least baseline social standards:

• S1 Workforce: Employment data including headcount, employment contracts, and workforce composition.
• S2 Workers in Value Chain: Supply chain labor practices, now with more streamlined assessment approaches for indirect suppliers.
• S3 Affected Communities: Impacts on local communities where material to your operations.
• S4 Consumers: Product safety, data privacy, and consumer-facing practices where applicable.

Governance Standards

Basic governance disclosures remain mandatory:

• G1 Board composition: Board diversity and expertise.
• G2 Ethics and compliance: Management of bribery, corruption, and business conduct risks.
• G3 Remuneration: Executive remuneration policies and pay equity metrics where relevant.

Practical Implementation Steps

Converting simplified ESRS requirements into action requires a structured approach. Here's a proven roadmap:

Step 1: Conduct Your Materiality Assessment

Start here. Before collecting a single data point, understand which ESG topics matter most to your business and stakeholders. Your materiality assessment should include:

• Stakeholder interviews (customers, investors, employees, suppliers)
• Industry benchmarking analysis
• Review of financial impacts and dependencies
• Assessment of operational and supply chain risks
• Prioritization matrix mapping financial and impact materiality

This assessment determines everything downstream: which standards apply, which metrics you must report, and how to prioritize limited resources.

Step 2: Perform a Gap Analysis

Against your materiality assessment, map what data you currently collect and what gaps exist. For example:

• Do you measure Scope 1 and 2 emissions? What data is missing?
• Do you track diversity metrics? Is the data accurate and complete?
• Do you monitor supply chain labor practices? How robust is this process?
• What systems would you need to implement to close gaps?

This gap analysis becomes your roadmap for data collection infrastructure investment.

Step 3: Develop Your Data Collection Strategy

For each material metric, define how you'll collect and verify data. Consider:

• Which data sources exist (utility bills, HR systems, supplier questionnaires, manufacturing equipment, etc.)?
• What systems must be modified or implemented to capture data?
• Who owns data quality and validation?
• What documentation and records must be maintained?
• Where are estimation methodologies required, and how will you justify estimates?

The simplified ESRS permits estimation and proxies where exact measurement is unreasonably burdensome. Document your estimation methodologies and justify their conservatism and reasonableness.

Step 4: Plan Your Reporting Timeline

Allocate realistic timelines for implementation. A typical timeline looks like:

• Months 1-2: Materiality assessment and stakeholder engagement
• Months 2-3: Gap analysis and systems review
• Months 3-6: Data collection infrastructure investment and process development
• Months 6-9: Pilot data collection and validation
• Months 9-12: Full year data collection and reporting

This timeline is illustrative; actual timelines depend on your current state, materiality scope, and available resources.

The Role of AI and Automation Tools

AI-powered tools are transforming ESRS implementation, making data collection, analysis, and reporting faster and more accurate. Key automation opportunities include:

• Emissions calculation: AI tools can ingest energy bills, manufacturing data, and logistics information to automatically calculate Scope 1, 2, and 3 emissions using standardized methodologies.
• Supply chain assessment: Automated supplier questionnaires and assessment platforms streamline supply chain data collection at scale.
• Data integration: Tools that connect your HR, accounting, manufacturing, and operational systems to automatically pull sustainability-relevant data.
• Report generation: Platforms that convert raw sustainability data into formatted ESRS reports, reducing manual compilation time.

For mid-market companies, strategic use of these tools can compress implementation timelines by 30-40% while improving data quality and auditability.

Common Implementation Challenges and Solutions

Challenge 1: Scope 3 Emissions Data from Suppliers

Scope 3 emissions often comprise the majority of a company's carbon footprint, yet suppliers are frequently reluctant or unable to provide detailed emissions data.

Solution: The simplified ESRS permits the use of spend-based or activity-based estimation methodologies where supplier data is unavailable. Document your estimation approach and apply conservative assumptions. Over time, engage suppliers to improve data quality.

Challenge 2: Supply Chain Labor Practice Visibility

Understanding labor practices across a complex supply chain is resource-intensive.

Solution: Use risk-based sampling approaches. Focus your detailed assessment on high-risk suppliers (labor-intensive industries, developing economies, specific risk categories). Use industry benchmarks and proxy data for lower-risk segments. The simplified standards explicitly permit this proportionate approach.

Challenge 3: Historical Data Gaps

Many companies lack clean historical data needed for trend analysis.

Solution: Disclose gaps clearly and explain your approach to data quality improvement. Use your first reporting year to establish baseline data and improve systems. Subsequent years will show improvement in data completeness and accuracy, which is itself a positive signal to stakeholders.

Next Steps: From Understanding to Action

The simplified ESRS makes sustainability reporting achievable for mid-market companies. The key to successful implementation is to start with clarity: understand your material topics, then build data collection systems to measure and report on them.

Many mid-market companies find that the cost of comprehensive ESRS implementation is far lower than expected—often €2,500-€5,000 for initial assessment and implementation planning, and €1,500-€3,000 for ongoing annual reporting once systems are established.

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