Double Materiality Assessment
Belgium

Double materiality assessment in Belgium: Wet tot omzetting van de CSRD (CSRD Transposition Act, amending the Wetboek van Vennootschappen en Verenigingen)

Belgium transposed the CSRD through amendments to the Wetboek van Vennootschappen en Verenigingen (Code of Companies and Associations), following the federal legislative process. Belgium's transposition aligns with the EU directive's phasing timeline. The ESRS delegated acts apply directly, meaning the double materiality assessment requirements in ESRS 1.20-33 are not modified by national legislation. Belgium's position as host to EU institutions and numerous international organisations gives its corporate population a distinctive character. Many Belgian entities are subsidiaries of multinational groups, which means the double materiality assessment may need to be coordinated between the Belgian subsidiary (reporting under CSRD in its own right) and the group parent (which may report under CSRD, UK SRS, or a third-country equivalent). The Belgian transposition addresses this through the CSRD's subsidiary exemption provisions, but entities must verify whether the exemption conditions are met.

Regulatory context: Autoriteit voor Financiële Diensten en Markten (FSMA)

The FSMA enforces sustainability reporting for Belgian listed entities. The FSMA has aligned its enforcement priorities with ESMA's guidance and has indicated that the double materiality assessment will be a review focus in early CSRD reporting cycles. The FSMA's approach follows the same model as its financial reporting enforcement: risk-based selection of entities for detailed review, with the power to require corrections. The Instituut van de Bedrijfsrevisoren / Institut des Réviseurs d'Entreprises (IBR/IRE) regulates the bedrijfsrevisor / réviseur d'entreprises profession in Belgium. The IBR/IRE has published guidance on sustainability assurance, building on the existing Belgian standard for assurance on non-financial information. Belgian réviseurs performing sustainability assurance must meet additional competence requirements set by the IBR/IRE. The College van Toezicht op de Bedrijfsrevisoren (CTR) oversees audit quality and will extend its inspection programme to sustainability assurance engagements. Belgium's federal structure (Flanders, Wallonia, Brussels-Capital Region) creates an additional layer of environmental regulation. Regional environmental permits, waste management regulations, and nature conservation rules differ across the three regions, which affects the evidence base for the double materiality assessment on environmental topics. Entities operating across multiple Belgian regions must collect environmental data from different regulatory sources.

Practical guidance for Belgium

Belgian entities should start the double materiality assessment by mapping their activities to ESRS 1 Appendix A sustainability matters. For entities that are subsidiaries of larger groups, coordinate the assessment with the group-level process to ensure consistency while maintaining entity-level specificity. The CSRD requires the materiality assessment at the reporting entity level, not just at group level. Engage stakeholders per ESRS 1.24. Belgian labour law provides strong stakeholder structures through the Ondernemingsraad / Conseil d'Entreprise (works council) and the Comité voor Preventie en Bescherming op het Werk / Comité pour la Prévention et la Protection au Travail (health and safety committee). These bodies provide direct input for S1 workforce topics. For environmental topics, use data from regional environmental permits and the entity's environmental management system (EMAS or ISO 14001 if applicable). Belgium's strong presence in the chemical, pharmaceutical, and logistics sectors means that many entities face complex environmental materiality across E1, E2, and E3. The Port of Antwerp-Bruges industrial complex alone hosts entities with concentrated chemical, petrochemical, and logistics operations that trigger materiality across most ESRS environmental standards.

Audit expectations

Belgian bedrijfsrevisoren providing limited assurance on sustainability reports must comply with the IBR/IRE's professional standards and meet the sustainability assurance competence requirements. The assurance engagement covers the full sustainability statement, including the entity's description of its double materiality assessment process (ESRS 2 IRO-1). The assurance provider must evaluate whether the process meets ESRS 1.20-33 requirements and whether the conclusions are supported by evidence. The CTR will inspect sustainability assurance engagements alongside financial statement audits. Given Belgium's relatively small population of large listed entities (compared to Germany or France), the CTR's inspection coverage is expected to be proportionally higher, meaning Belgian entities and their assurance providers face a greater probability of inspection in early reporting cycles.

Belgium-specific considerations

Belgium's linguistic divide (Dutch-speaking Flanders, French-speaking Wallonia, bilingual Brussels) affects sustainability reporting in practical ways. Entities must file reports in the language of their registered office, and sustainability statements must be available in the language of affected stakeholders where relevant to stakeholder engagement under ESRS 1.24. Multinational entities headquartered in Brussels may need to manage reporting in multiple languages. The Belgian federal government's National Energy and Climate Plan (NECP) sets country-level targets for emissions reduction, renewable energy, and energy efficiency. These targets create financial materiality for Belgian entities through anticipated regulatory tightening on industrial emissions, transport, and buildings. The Flemish Klimaatplan, Walloon Plan Air Climat Énergie, and Brussels' regional climate plan add region-specific targets that vary in ambition. Belgium's role as a logistics hub (Port of Antwerp-Bruges, Brussels Airport, road freight corridors) means that logistics entities face specific E1 and E2 materiality from transport emissions and air pollution. The Belgian government's planned road pricing scheme for heavy goods vehicles will create additional financial materiality for logistics companies operating in Belgium.

Common inspection findings

The FSMA's initial review of early CSRD adopters found that Belgian entities with existing sustainability reports often did not perform a formal double materiality assessment, assuming their previous voluntary disclosures were sufficient.

The CTR's inspection of financial statement audits identified that auditors were not consistently considering sustainability-related risks (climate, environmental liabilities) in their financial statement audit procedures, indicating a gap that will also affect sustainability assurance quality.

The FSMA flagged that Belgian subsidiaries of foreign groups were delegating the materiality assessment entirely to the group parent without adapting it to the Belgian entity's specific circumstances.

The IBR/IRE identified that assurance providers lacked practical experience with the ESRS 1.20-33 methodology, leading to reliance on checklists rather than substantive evaluation of the entity's assessment process.

The FSMA noted that Belgian entities in the chemical sector had well-developed environmental data (from Seveso and E-PRTR reporting) but were not consistently mapping this data to the ESRS topic structure.