CSRD explained:the practical reporting guide.
A plain-English guide to the Corporate Sustainability Reporting Directive: what it requires, who must comply and when, what double materiality means, and how to report without drowning in spreadsheets.
This guide is educational and reflects the finalized, simplified ESRS the European Commission adopted on 3 July 2026. CSRD scope and timelines changed substantially through the EU “Omnibus” package, so confirm your specific obligations with qualified advisors and the latest EU guidance.
What is the CSRD?
The Corporate Sustainability Reporting Directive is an EU law that dramatically expands corporate sustainability reporting. It requires in-scope companies to disclose standardized information about their environmental, social, and governance impacts and risks — following the European Sustainability Reporting Standards (ESRS), assessed through double materiality, and backed by independent assurance.
In practice, that means sustainability information now sits alongside financial reporting in seriousness: standardized, evidenced, audited, and published. It replaces and widens the older Non-Financial Reporting Directive (NFRD), bringing far more companies into scope with far more to disclose.
Who must comply, and when
The picture changed significantly in 2025–2026. The EU’s “Omnibus” simplification package narrowed who has to report, delayed the later waves (the adopted “stop-the-clock” directive), and cut the volume of required data. Here is where things stand — always confirm the current rules for your own situation.
Who is in scope
The 2025 “Omnibus” package narrows CSRD toward the largest companies — broadly those above 1,000 employees, with a turnover threshold around €450 million.
That is expected to cut the number of covered companies by roughly 90% versus the original scope, which reached down to 250 employees.
Simplified standards
On 3 July 2026 the European Commission adopted a finalized, streamlined set of ESRS.
The revision removed on the order of 70% of datapoints (about 61% of the mandatory ones) to ease the reporting burden.
Delayed timelines
The Omnibus package “stopped the clock,” pushing later reporting waves back by about two years.
Companies already reporting continued; others gained more time to prepare.
Non-EU groups
Large non-EU groups with significant EU turnover and an EU presence remain a later, separate wave.
Confirm the current threshold and first reporting year for your group, as these were also revised.
Double materiality assessment
Double materiality is the assessment that decides what you actually have to report. You look at every sustainability topic from two directions — and a topic counts if it is material from either one.
Getting this assessment right is the foundation of a defensible CSRD report. A weak or undocumented assessment is one of the first things assurance providers and regulators will challenge.
Impact materiality
How your business affects people and the environment — the “inside-out” view.
Financial materiality
How sustainability issues affect your business — the “outside-in” view on risk and value.
The ESRS data points you must disclose
The European Sustainability Reporting Standards are the detailed rulebook behind CSRD. What you report depends on your double materiality results, but the standards are organized into these areas:
Environment (E1–E5)
Climate change, pollution, water and marine resources, biodiversity and ecosystems, and resource use and the circular economy.
Social (S1–S4)
Your own workforce, workers in the value chain, affected communities, and consumers and end-users.
Governance (G1)
Business conduct, including anti-corruption, political engagement, and the management of supplier relationships.
Cross-cutting standards
General requirements and general disclosures (ESRS 1 and ESRS 2) that apply on top of the topical standards.
CSRD vs NFRD vs SEC climate rules
CSRD is often confused with the rules it replaced and with US disclosure requirements. Here is how they differ.
CSRD
The EU directive that expands who must report and what they disclose. Reporting follows the ESRS, uses double materiality, and requires independent assurance.
NFRD
The older Non-Financial Reporting Directive that CSRD replaces and widens — far fewer companies, lighter requirements, and no standardized ESRS.
SEC climate rules (US)
A separate, US-focused disclosure regime centered on financial materiality and climate. It is narrower than CSRD and has followed its own contested legal path.
Common CSRD reporting mistakes
Most CSRD programs run into the same avoidable problems. Knowing them early is the cheapest way to stay on track.
Treating it as a finance-only or sustainability-only project
CSRD sits across finance, sustainability, legal, procurement, and operations. Siloed ownership is the most common reason programs stall.
Starting the data work too late
Value-chain and Scope 3 data take months to collect. Teams that wait until the reporting year run out of runway.
Skipping a rigorous double materiality assessment
The assessment decides what you actually have to disclose. A weak one leads to gaps auditors and regulators will flag.
Keeping evidence in scattered spreadsheets
Under assurance, every number needs a traceable source, method, and reviewer. Disconnected files do not hold up.
Ignoring related rules like the CSDDD
Due-diligence obligations under the CSDDD overlap with CSRD disclosures; planning them separately duplicates work.
How Hydrus runs CSRD reporting for you
Most teams do not want to become full-time CSRD reporters — they want the finished, audit-ready result. Hydrus is built for exactly that: an AI-native platform that captures and structures your data, run by experts who turn it into a compliant report. You get the outcome, not the homework.
- We run your double materiality assessment and document it defensibly.
- We collect and structure the ESRS data points, including value-chain and Scope 3.
- Every figure keeps its source, method, and reviewer — ready for assurance.
- We keep your program current as thresholds and timelines change.
CSRD questions, answered
What is the CSRD in simple terms?
The Corporate Sustainability Reporting Directive is an EU law that requires many companies to report detailed, standardized, and independently assured information about their environmental, social, and governance impacts and risks — using the European Sustainability Reporting Standards (ESRS).
Who has to comply with the CSRD?
Large EU companies, listed companies, and certain large non-EU groups with significant EU activity fall in scope, phased in over time. The 2025 “Omnibus” package sharply narrowed this — CSRD now points toward the largest companies (broadly above 1,000 employees, with a turnover threshold around €450 million), roughly 90% fewer companies than the original scope that reached down to 250 employees. Confirm your current obligation against the latest EU guidance.
What is double materiality?
Double materiality means you assess your topics from two directions: how sustainability issues affect your business (financial materiality) and how your business affects people and the environment (impact materiality). A topic is reportable if it is material from either angle.
What are the ESRS?
The European Sustainability Reporting Standards are the detailed rulebook that says what to disclose under CSRD. They cover environmental, social, and governance topics, plus cross-cutting general requirements.
How is the CSRD different from the CSDDD?
The CSRD is a reporting directive — it governs what you disclose. The CSDDD (Corporate Sustainability Due Diligence Directive) is a conduct directive — it governs the due diligence you must perform across your value chain. They overlap, so many companies plan them together.
Do CSRD reports need to be audited?
Yes. CSRD introduces mandatory assurance of sustainability information, beginning with limited assurance, with the possibility of moving to reasonable assurance over time. That is why traceable, well-documented evidence behind every figure matters so much.
Facing AI regulation too?
The same team and evidence engine stands up your EU AI Act program end to end — inventory, risk classification, controls, and audit-ready documentation.
Let Hydrus run your CSRD program end to end.
Book a readiness call and we will map exactly what you have to report under CSRD and how fast we can get you there.