For companies in scope of CSRD, the EU Taxonomy is one of the most technically demanding parts of sustainability reporting.
It looks deceptively simple from the outside. The Taxonomy is a classification system for environmentally sustainable economic activities, with thresholds that define what counts as "green" and what does not. In practice, applying it inside a real business with multiple revenue streams, legacy reporting systems, and complex value chains is where the difficulty sits.
ESG teams preparing their first or second Taxonomy disclosure tend to run into the same recurring questions. What is eligible? What is aligned? Where do the technical screening criteria actually bite? How do the do-no-significant-harm assessments work in practice? And how does any of this translate into the KPIs that need to appear in the sustainability statement?
This guide walks through how EU Taxonomy alignment works in practice, the most common pitfalls, and how to approach the disclosure without losing weeks to interpretation debates.
What the EU Taxonomy is, in plain terms
The EU Taxonomy is a classification framework that defines whether an economic activity qualifies as environmentally sustainable. It does this through six environmental objectives:
- Climate change mitigation
- Climate change adaptation
- Sustainable use and protection of water and marine resources
- Transition to a circular economy
- Pollution prevention and control
- Protection and restoration of biodiversity and ecosystems
For each environmental objective, the Taxonomy lists specific economic activities and the technical screening criteria that determine whether those activities are making a substantial contribution. Activities that meet the criteria, do no significant harm to the other objectives, and meet minimum social safeguards are considered Taxonomy-aligned.
This sounds straightforward. The complexity sits in how those concepts map to a company's actual revenues, capital expenditure, and operating expenditure.
Eligibility versus alignment
The single most common confusion in Taxonomy reporting is the difference between eligibility and alignment.
Eligibility is the first filter. An activity is Taxonomy-eligible if it appears in the list of activities covered by the Taxonomy regulation. Eligibility says nothing about whether the activity is being performed sustainably. It only says that the Taxonomy has rules for that type of activity.
Alignment is the higher bar. An aligned activity is one that is eligible, meets the technical screening criteria for substantial contribution, satisfies the do-no-significant-harm requirements, and complies with minimum social safeguards.
In other words: every aligned activity is eligible, but not every eligible activity is aligned. Reporting teams often have to disclose three sets of numbers — total, eligible, and aligned — and any inconsistency between them is one of the first things auditors and analysts pick up.
How the KPIs work
Taxonomy disclosure is structured around three KPIs: turnover, capital expenditure, and operating expenditure.
Turnover KPI captures the share of revenue derived from Taxonomy-aligned activities. It is the most visible number externally. Investors and customers tend to focus on it because it shows what the business actually does, not what it plans to do.
CapEx KPI captures the share of capital expenditure that is either spent on aligned activities, on assets used for aligned activities, or as part of a credible CapEx plan to bring activities into alignment within five to ten years. The CapEx KPI is where forward-looking transition stories often live.
OpEx KPI captures operating expenditure linked to aligned activities, particularly maintenance, R&D, and short-term operational spend that supports green activities. For some sectors, OpEx is the most material lens; for others, it is relatively minor.
Together, these three KPIs paint a picture of where the business is today, where it is investing, and where it is operating. A well-prepared disclosure presents them consistently, with clear methodology, and with a narrative that links the numbers to the company's strategy.
Technical screening criteria in practice
The technical screening criteria are where the Taxonomy becomes specific. Each eligible activity has its own set of criteria that define what substantial contribution looks like in numerical and operational terms.
For climate change mitigation, criteria often relate to greenhouse gas emissions thresholds, energy efficiency benchmarks, or alignment with a sectoral decarbonisation pathway. For circular economy activities, criteria may focus on material recovery rates, design for durability, or use of secondary raw materials. For water-related activities, criteria may relate to water stress assessments, leakage thresholds, or treatment standards.
The complexity is that the criteria are highly sector-specific. A manufacturer evaluating whether a particular product line aligns under the Taxonomy is unlikely to find a one-size-fits-all answer. Mapping internal data to the technical screening criteria is usually where the largest amount of preparation time goes.
A practical approach is to build an internal mapping document for each material activity, listing the relevant criteria, the data sources used to test compliance, and the conclusion. This becomes essential for both internal review and external assurance.
Do no significant harm
Even an activity that meets the technical screening criteria for substantial contribution does not automatically qualify as aligned. It also has to pass the do-no-significant-harm assessment for the other five environmental objectives.
This is where many companies discover that what looks like a strong green activity has hidden exposures. A renewable energy installation may make a substantial contribution to climate mitigation, but if it has not been assessed for biodiversity impact at the site level, the alignment claim is incomplete. A circular economy activity may pass on resource use but raise concerns under pollution prevention.
Do-no-significant-harm assessments are operational. They require evidence at the site, project, or activity level — not just at corporate level. That is one reason Taxonomy reporting often pulls in operational, environmental, and engineering teams who are not normally part of sustainability reporting.
Minimum social safeguards
The final test for alignment is compliance with minimum social safeguards. The Taxonomy requires alignment with the OECD Guidelines for Multinational Enterprises, the UN Guiding Principles on Business and Human Rights, the ILO core labour conventions, and the International Bill of Human Rights.
In practice, this means companies need to show that they have processes in place for human rights due diligence, anti-corruption controls, fair competition, and tax compliance. Many large organisations already have most of these processes in some form, but the Taxonomy requirement is to evidence them clearly enough that compliance with the safeguards can be demonstrated.
The minimum social safeguards element of Taxonomy alignment has been the subject of significant interpretation work, including from the Platform on Sustainable Finance. Reporting teams should expect this area to keep evolving.
How Taxonomy interacts with CSRD and SFDR
The EU Taxonomy does not exist in isolation. It is one part of a broader sustainable finance architecture that also includes CSRD and SFDR.
Under CSRD, in-scope companies disclose Taxonomy KPIs as part of the sustainability statement. ESRS E1 picks up the climate side directly, and the Taxonomy KPIs sit alongside other ESRS disclosures. Internal consistency across all of these is important: the Taxonomy CapEx plan and the ESRS E1 transition plan should reinforce each other, not contradict.
Under SFDR, financial market participants use Taxonomy data to inform their disclosures, particularly for Article 8 and Article 9 funds. Investee company Taxonomy disclosures feed directly into fund-level disclosures. That creates an upstream pull on corporate Taxonomy reporting: asset managers increasingly need their portfolio companies to disclose Taxonomy KPIs, which means corporate teams need to prepare for both regulatory requirements and investor questions.
Common pitfalls
A few patterns come up repeatedly in Taxonomy reporting.
The first is treating Taxonomy as a finance-only exercise. Although the KPIs are financial, the alignment assessment is operational. Without input from environmental, technical, and operational teams, alignment claims are usually weak.
The second is over-claiming alignment. It is tempting to push borderline activities into the aligned bucket, but the technical screening criteria, do-no-significant-harm tests, and minimum social safeguards together create a high bar. Overstated alignment is one of the fastest ways to lose credibility with assurance providers and analysts.
The third is under-claiming. The opposite problem is also common. Companies that have not invested in mapping or evidence may end up reporting low alignment numbers simply because they cannot demonstrate compliance with criteria they actually meet. This is a particular risk in sectors where alignment thresholds are achievable but require careful documentation.
The fourth is inconsistency between Taxonomy and ESRS disclosures. The Taxonomy CapEx KPI and the ESRS E1 transition plan, the Taxonomy turnover KPI and the business model description, the Taxonomy social safeguards and the ESRS S-series disclosures — all need to tell a coherent story. Inconsistencies surface fast under assurance.
The fifth is leaving everything to the last quarter. Taxonomy assessments take time, especially the first time through. Mapping activities, gathering evidence, performing do-no-significant-harm assessments, and reviewing minimum social safeguards across a large organisation cannot reasonably be compressed into a few weeks.
How to prepare
A practical preparation sequence usually looks like this:
- Map the company's activities to the Taxonomy's economic activity list to identify what is eligible
- For each eligible activity, identify the relevant technical screening criteria
- Gather data and evidence at the activity, site, or project level to test the criteria
- Perform do-no-significant-harm assessments using the relevant operational data
- Verify minimum social safeguards through governance and compliance processes
- Calculate the turnover, CapEx, and OpEx KPIs based on aligned activities
- Document the methodology, assumptions, and judgements taken
- Reconcile Taxonomy disclosures with ESRS disclosures for internal consistency
- Build the evidence file for assurance
This sequence works best when the work is owned cross-functionally rather than parked entirely in the sustainability team. Finance, operations, legal, environmental, and HR teams all have a role.
What good looks like
A high-quality Taxonomy disclosure does several things well.
It distinguishes clearly between eligibility and alignment. It presents the three KPIs with consistent methodology and reconcilable numbers. It links the CapEx KPI to a credible transition narrative. It provides clear evidence on technical screening criteria, do-no-significant-harm, and minimum social safeguards. It is internally consistent with the rest of the sustainability statement and the financial statements. And it is honest about where data and methodology are still developing.
Companies that try to position the Taxonomy purely as a marketing opportunity tend to produce disclosures that read as overstated. Companies that approach it as a structured, evidence-based reporting requirement tend to produce disclosures that hold up under scrutiny — and, increasingly, attract more constructive engagement from investors.
Final thought
The EU Taxonomy is one of the most technically demanding parts of CSRD reporting, but it is also one of the most useful. Done well, it forces a clear-eyed view of where the business actually is on its sustainability journey, where investment is going, and where the gaps remain.
For ESG teams, the goal is not a perfect alignment number on day one. The goal is a disclosure that is grounded in evidence, internally consistent, and capable of improving year on year. That is what builds credibility with investors, regulators, and assurance providers — and it is what turns Taxonomy reporting from a compliance exercise into a genuine input to strategy.