CSRD in Spain: Complete Guide to Preparing Your First Sustainability Report Under ESRS Standards

CSRD: the biggest change in corporate reporting since mandatory accounting

The Corporate Sustainability Reporting Directive (CSRD), formally Directive (EU) 2022/2464, is the centrepiece of the European Union’s sustainable finance strategy and represents the most ambitious reform of corporate reporting since the introduction of mandatory accounting. Its aim is to make sustainability information as reliable, comparable, and auditable as financial information.

CSRD replaces the Non-Financial Reporting Directive (NFRD) of 2014, which had produced highly heterogeneous, barely comparable sustainability reports of often limited practical utility. With CSRD, Europe imposes a single standard — the ESRS — with structured formats, mandatory verification, and digital integration.

Who must report and when: the CSRD calendar in Spain

CSRD expands the scope of obligated companies in stages:

FY2024 → Report in 2025: Companies already subject to the former NFRD (large listed companies with more than 500 employees) publish their first CSRD report, now under ESRS standards.

FY2025 → Report in 2026: The largest quantitative leap. All large Spanish companies — listed or not — meeting two of three criteria: more than 250 employees, net turnover above €50M, or balance sheet assets above €25M. In Spain, this affects several thousand companies that had not previously reported sustainability formally.

FY2026 → Report in 2027: SMEs listed on EU regulated markets, with the option to use the simplified ESRS for SMEs standard.

FY2028 → Report in 2029: Companies from third countries (outside the EU) with EU turnover above €150M and significant EU subsidiaries or branches.

Beyond the formal calendar, there is market pressure that effectively advances reporting timelines: suppliers to CSRD-subject large companies receive information requirements about their ESG data as part of the value chain that CSRD companies must report.

The ESRS standards: structure and content

The European Sustainability Reporting Standards (ESRS) are the technical core of CSRD. EFRAG (the European Financial Reporting Advisory Group) developed them and the European Commission has adopted them through delegated regulations.

ESRS 1 — General requirements: Contains no specific disclosures but establishes the methodological principles: double materiality concept, value chain scope, information quality principles, and the materiality analysis process.

ESRS 2 — General disclosures: The only standard mandatory for all companies regardless of the materiality analysis. It covers the company’s business context, sustainability governance, strategy, and the materiality analysis process. It is the most narrative-intensive standard.

Environmental standards: E1 (climate change, including GHG emissions scopes 1, 2, and 3, transition plan targets), E2 (air, water, and soil pollution and substances of concern), E3 (water and marine resources), E4 (biodiversity and ecosystems), E5 (resource use, waste, and circular economy).

Social standards: S1 (own workforce: working conditions, equality, diversity, health and safety), S2 (workers in the value chain), S3 (affected communities), S4 (consumers and end-users).

Governance standard: G1 (business conduct: ethics, corruption and bribery, management of supplier and customer relationships, tax information).

For each material standard, companies must disclose their strategy, policies, targets, actions, and results (SBTI framework: Strategy, Business model, Targets, Indicators), in addition to the standard’s specific quantitative indicators.

The double materiality analysis: where to start

The double materiality analysis is the process that determines which ESRS topics are relevant for the specific company and, therefore, which ones it must report on in depth. It is the mandatory starting point for all CSRD preparation and also the aspect companies find most daunting due to its methodological novelty.

The double materiality process, as per EFRAG guidance, has the following steps:

1. Context understanding: Analyse the business model, activities, value chain, and geographic areas where the company operates to understand where impacts, risks, and opportunities may arise.

2. Identification of impacts, risks, and opportunities (IROs): For each ESRS topic (climate change, water, diversity, etc.), identify the company’s actual and potential impacts on people and the environment, and the financial risks or opportunities that topic creates for the company.

3. Materiality assessment: Evaluate the significance of identified IROs against criteria of severity (for impacts) and financial magnitude and likelihood (for risks/opportunities). IROs that exceed established thresholds are material.

4. Stakeholder consultation: ESRS requires that the materiality analysis incorporates the perspective of the company’s relevant stakeholder groups (employees, customers, suppliers, local communities, investors).

5. Documentation and validation: The double materiality process must be documented in a way that allows the external verifier to validate both the process followed and the conclusions reached.

BMC coordinates this process using the EFRAG methodology, adapted to each company’s specific sector, size, and value chain. Contact us to start your company’s double materiality analysis.

CSRD verification: preparing for sustainability assurance

External verification of the CSRD report is mandatory and represents a fundamental difference from previous voluntary sustainability reports. It means the company must:

Have traceable data: The report’s quantitative indicators must be traceable to their source — measurements, invoices, contracts, HR data — so the verifier can validate them.

Have documented processes: The internal processes for collecting, calculating, and validating ESG data must be documented and executed consistently.

Maintain evidence records: The double materiality analysis, stakeholder consultations, impact assessments, and sustainability policies must be formally documented and archived.

Have internal controls: ESG data management systems must have quality controls equivalent to those existing in the financial function.

Our CSRD reporting team works with companies to establish these evidence systems from the first reporting year, ensuring the verification process is efficient and minimising the risk of qualifications in the verified report.

CSRD and the EU Taxonomy: the green activity dimension

Many companies approaching CSRD for the first time underestimate the complexity of the EU Taxonomy Regulation dimension. CSRD requires companies to disclose their alignment with the EU Taxonomy — the classification system defining which economic activities qualify as environmentally sustainable.

Companies must report two metrics for each Taxonomy-eligible activity:

Taxonomy-eligible turnover, capex, and opex: The proportion of economic activities that could in principle qualify as sustainable under the Taxonomy, regardless of whether they currently meet the technical criteria.

Taxonomy-aligned turnover, capex, and opex: The proportion that actually meets the Taxonomy’s technical screening criteria, does not significantly harm other environmental objectives (DNSH principle), and meets minimum social safeguards.

The Taxonomy alignment calculation requires detailed technical analysis activity by activity, applying the criteria established in the Taxonomy’s delegated acts. For many companies, this is technically complex and requires specialist support.

BMC’s ESG and sustainability team integrates Taxonomy reporting into the broader CSRD process, ensuring consistency between the Taxonomy disclosures and the rest of the sustainability report and coordinating with the financial team for the capex and opex calculations.

CSRD practical preparation: the five most common gaps in Spanish companies

Companies approaching their first CSRD report in 2025 or 2026 are discovering that the gap between their current state and what CSRD requires is wider than anticipated. The five gaps most commonly identified in BMC’s readiness assessments with Spanish companies are:

1. Missing Scope 3 emissions data. The climate change standard ESRS E1 requires disclosure of Scope 3 greenhouse gas emissions — those generated indirectly through the company’s value chain, including purchased goods and services (upstream) and product use and disposal (downstream). Collecting Scope 3 data requires supplier engagement, spend-based or activity-based calculation methodologies, and a materiality assessment to determine which Scope 3 categories are significant. Spanish companies with supply chains in food, manufacturing, or construction typically find that Scope 3 represents the majority of their total carbon footprint — and collecting this data takes two or three reporting cycles to mature. Starting the process before the first reporting deadline is essential.

2. Absence of a formal double materiality methodology. Most Spanish companies that have produced previous voluntary sustainability reports (under GRI standards or similar) have conducted some form of materiality analysis. CSRD’s double materiality requirement goes further: it requires simultaneous assessment of impact materiality and financial materiality, using an IRO (Impact, Risk, Opportunity) framework documented in a way that can be audited by the external verifier. GRI-style “importance to stakeholders” matrices do not meet this standard. BMC rebuilds the materiality analysis from the ESRS 1 methodology for clients whose previous framework was not CSRD-compliant.

3. Absence of ESG governance structure. ESRS 2 requires detailed disclosure on sustainability governance: which board-level body oversees sustainability strategy, how sustainability risks and opportunities are integrated into board decision-making, and what management-level roles are responsible for sustainability topics. Spanish companies that have treated sustainability as a communications or marketing function — rather than a governance function — must restructure their internal accountability to meet ESRS 2 requirements before the first report.

4. Insufficient supply chain data. ESRS S2 (workers in the value chain) and ESRS E4 (biodiversity) require information that cannot be generated from internal data alone. Companies must identify and assess their most significant suppliers and understand the social and environmental conditions in their supply chains. This requires supplier questionnaires, third-party audit programs for high-risk suppliers, and a systematic approach to supply chain due diligence that most Spanish companies have not previously applied.

5. Digital report format — iXBRL tagging. CSRD requires that sustainability reports be submitted as part of the annual management report in XHTML format with iXBRL tagging under the European Single Electronic Format (ESEF). Most Spanish companies — and many of their software vendors — are not yet set up to produce tagged sustainability reports. This is an operational requirement that must be addressed well in advance of the filing deadline; it cannot be resolved in the week before submission.

Key regulatory references for CSRD compliance in Spain

Companies preparing for CSRD should be aware of the primary legal instruments that govern their obligations:

• Directive (EU) 2022/2464 (CSRD): The parent directive, effective 5 January 2023, amending Directive 2004/109/EC (Transparency Directive), Directive 2006/43/EC (Statutory Audit Directive), and Directive 2013/34/EU (Accounting Directive).
• Delegated Regulation (EU) 2023/2772: The first set of European Sustainability Reporting Standards (ESRS), adopted 22 December 2023, applicable to large companies for financial years starting 1 January 2024.
• Spanish transposition: Spain is in the process of transposing CSRD into national law. The transposition must incorporate CSRD into the Ley de Auditoría de Cuentas and Código de Comercio, and establish the national enforcement and penalties regime. Until transposition is complete, the Directive’s requirements remain the reference standard.
• EFRAG guidance documents: EFRAG has published detailed implementation guidance on the double materiality analysis process, value chain reporting, and sector-specific supplements (currently in development). These are not legally binding but are the primary technical reference for CSRD preparers and verifiers.