Digital tagging of sustainability statements

What is digital tagging?

Each disclosure is linked to an element in a taxonomy, a structured dictionary of reporting concepts, with attributes such as the reporting entity, period, unit and any breakdown. Using Inline XBRL, the tags sit inside the XHTML report, so the same document can be read by people and processed by machines. Numeric datapoints are tagged individually; narrative disclosures are tagged as blocks of text. See ESRS 2 general disclosures.

What does the CSRD require?

Companies in scope prepare their management report in ESEF, the format already used for annual financial reports of listed companies, and the sustainability statement, including the disclosures required by Article 8 of the EU Taxonomy Regulation, is to be marked up according to a digital taxonomy. The detailed rules come through an amendment to the ESEF Regulation, drafted by ESMA using EFRAG's taxonomy and adopted by the Commission. Until then, companies prepare the report in ESEF but do not have to tag the sustainability statement. Assurance under the CSRD also covers compliance with the tagging requirements once they apply. See the CSRD after the Omnibus.

What is the ESRS XBRL taxonomy?

EFRAG's taxonomy translates the ESRS into XBRL elements, one for each datapoint, with data types for numeric, semi-narrative and narrative information, dimensions for breakdowns such as by country, scope or gender, and links to the standards. EFRAG submitted a taxonomy for the first set of ESRS in August 2024, but the revised ESRS changed many datapoints, so it published a list of datapoints for the revised standards in August 2026 and a draft taxonomy in September 2026. A separate taxonomy covers the Article 8 disclosures. See the revised ESRS.

Digital tagging in practice: three tags from one statement

A manufacturer's sustainability statement includes a scope 1 figure, headcount by country and a narrative on its transition plan. Each would be tagged differently.

The scope 1 figure is a single numeric fact with a unit and period. The headcount uses a country dimension, one fact per country. The transition plan is a text block, tagged as a whole, with key numbers inside it tagged individually where the taxonomy has elements for them. Consistent definitions, units and periods across the report make tagging far easier. See ESRS E1 and ESRS S1.

When will tagging become mandatory?

No date has been set. EFRAG expects to send its final taxonomy for the revised ESRS to ESMA and the Commission by the end of 2026; ESMA then prepares draft regulatory technical standards, and the Commission amends the ESEF Regulation, which typically sets a start date and may phase in the level of detail. Companies can follow the consultation and prepare their data structures in the meantime. See CSRD wave 1 relief.

What about the ISSB and other jurisdictions?

The IFRS Foundation publishes the IFRS Sustainability Disclosure Taxonomy, covering IFRS S1 and S2, so that jurisdictions adopting the ISSB standards can require tagged filings. EFRAG also provides a digital template and XBRL taxonomy for the VSME, the basis of the EU's voluntary standard for smaller companies. Common taxonomy architecture helps companies reporting under several frameworks reuse their tagged data. See ISSB adoption by country and the voluntary standard.

How should companies prepare?

Map each reported datapoint to its source and owner, store figures in a structured format rather than only in documents, use consistent units, periods and boundaries, and choose reporting software that can produce Inline XBRL. Draft the sustainability statement so that each required datapoint is clearly identifiable. Because the financial statements are already tagged in ESEF, the finance team's existing tagging process is a good starting point. See building a GHG inventory.

This guide is general information. It is not tax or legal advice for your situation.