CSRD 2026: The Real Challenges of Sustainability Reporting for Large Groups

The real problem: non-homogeneous data from global operations

For a CAC 40 company or any large group with operations in dozens of countries, CSRD compliance is fundamentally a data aggregation problem. Each subsidiary, joint venture, and supply chain partner measures environmental and social impact differently. Water consumption metrics in Brazil do not match those in Germany. Biodiversity assessments in Southeast Asia use different frameworks than those in the EU.

The regulation requires companies to report beyond Excel-based consolidation. Yet the vast majority of multinationals still rely on manual spreadsheet collection from local teams, with all the inconsistencies, delays, and error risks that entails. The obligation to report goes far beyond what these tools can handle reliably at scale.

E3, E4, E5: the environmental standards nobody is ready for

ESRS E1 (climate change) gets the most attention — largely because carbon accounting tools like Greenly have made greenhouse gas data accessible. But the real compliance gaps lie in the other environmental standards:

The auditor's dilemma: how OTI verify global sustainability reports

CSRD introduces mandatory third-party assurance of sustainability reports by an independent auditor (Organisme Tiers Indépendant, or OTI — sometimes called a "green auditor"). Initially under limited assurance, this will move to reasonable assurance by 2028, matching the rigor of financial auditing.

The practical question is: how does an OTI verify that a multinational group has correctly reported its biodiversity impact, water consumption, or social metrics across 30+ countries? The sheer volume and heterogeneity of data makes manual verification prohibitively time-consuming. This is where AI-powered regulatory intelligence becomes essential — not to replace the auditor, but to help them cross-reference declared data against regulatory requirements across jurisdictions and identify gaps or inconsistencies.

Phase 3 delayed: what the 2-year postponement means

The European Commission has postponed CSRD Phase 3 (listed SMEs) by two years. Originally due for FY 2026, it is now expected for FY 2028 reporting. This delay reflects the genuine difficulty of implementation, even for companies that were preparing. But it does not change the trajectory: the entire CAC 40 and most large European groups are already in scope under Phases 1 and 2, and the regulatory pressure on value chain reporting means their suppliers and partners are effectively drawn in too — regardless of whether they are formally subject to the directive.

The interconnected regulatory web: CSRD is never alone

CSRD compliance cannot be treated in isolation. Each ESRS standard connects to a broader regulatory ecosystem:

• →EU Taxonomy: CSRD-reported activities must be classified as sustainable under the Taxonomy framework
• →SFDR: Financial market participants use CSRD data to meet their own disclosure obligations
• →CS3D/CSDDD: Value chain due diligence requirements overlap with CSRD social standards (S1-S4)
• →Sapin II (France): Anti-corruption and transparency obligations that intersect with ESRS G1 (governance)
• →Duty of Vigilance / LkSG: French and German supply chain laws that predate and complement CS3D

Where AI adds value: regulatory intelligence, not carbon accounting

The sustainability compliance market already has established players solving specific pieces of the puzzle. Greenly has built a powerful carbon accounting engine through data scraping and automated emission factor calculation. Deepki solves the non-homogeneous data problem specifically for real estate asset managers. Sweep takes a transverse approach to ESG data management.

But none of these tools solve the regulatory tracking problem: which ESRS standards apply to you? What changed in the latest EFRAG interpretive guidance? How does the French transposition differ from the German one? When a new delegated act redefines biodiversity reporting thresholds, who tells you? This is where AI-powered regulatory intelligence fills the gap — mapping your obligations, tracking changes across jurisdictions, cross-referencing CSRD with EU Taxonomy, SFDR, Sapin II, and the Duty of Vigilance, and alerting your team in real-time.