ESMA / European Union

ESEF Validation & Compliance

Ensure your annual financial reports meet ESMA requirements. Validate iXBRL markup, report packages, and taxonomy extensions before filing.

What is ESEF?

The European Single Electronic Format (ESEF) is a mandatory reporting format for annual financial reports of companies listed on EU regulated markets. It was introduced by ESMA (European Securities and Markets Authority) under the Transparency Directive.

Since January 2020, listed companies must publish their annual financial reports in XHTML format with IFRS consolidated financial statements marked up using Inline XBRL (iXBRL).

ESEF ensures financial data is machine-readable while remaining human-readable, enabling automated analysis by investors, regulators, and researchers across the EU.

ESEF Technical Requirements

What your report must include

XHTML Format

Entire annual report in valid XHTML

iXBRL Tagging

Primary financial statements marked up in Inline XBRL

ESEF Taxonomy

IFRS taxonomy + extension elements properly anchored

Report Package

ZIP archive with META-INF structure per ESEF spec

ESEF Timeline

2020

ESEF became mandatory for annual reports (fiscal years starting 1 Jan 2020)

2021

First filing deadlines for most issuers. Block tagging of notes begins.

2022

Full roll-out. All primary statements must be tagged.

2024

Taxonomy 2024 with sustainability extensions

2026

Expected integration with ESRS (ESG reporting)

ESEF Compliance Checklist

Before you file, verify these requirements

  • XHTML document is valid and well-formed
  • All primary financial statements are tagged with iXBRL
  • Numeric values have correct decimals and scale
  • Extension elements are anchored to base taxonomy
  • Report package ZIP structure is correct (META-INF/reports/)
  • Calculation relationships are consistent
  • All required dimensions and members are present
  • Document renders correctly in iXBRL viewers

How Xerify Helps with ESEF

Validation

  • Full ESEF ruleset including 2024 updates
  • Report package structure validation
  • Extension taxonomy checks

Audit Trail

  • PDF validation certificates
  • Detailed error explanations
  • Version comparison (diff)

ESEF FAQs

Who must file ESEF reports?

All issuers with securities admitted to trading on EU regulated markets must file annual financial reports in ESEF format. This includes listed companies, banks, and insurers.

When is the ESEF filing deadline?

ESEF reports must be filed within 4 months of the financial year end (same as PDF reports). The exact deadline depends on your national regulator.

What taxonomy version should I use?

Use the ESEF taxonomy version specified by ESMA for your reporting period. For 2024 reports, use ESEF 2024 taxonomy based on IFRS 2023.

Do I need to tag the entire report?

Primary financial statements must be fully tagged. Notes are block-tagged. Management report and audit report are not required to be tagged.

What is anchoring and why does it matter?

Anchoring links extension elements to base taxonomy concepts, enabling comparability. Missing or incorrect anchoring is a common validation error.

Can I use custom CSS in my ESEF report?

Yes, but CSS must be embedded in the XHTML. External CSS files are not allowed. Styles should not interfere with iXBRL rendering.

What happens if my report fails validation?

Fix the errors and revalidate. Our error explanations help you understand what went wrong. The platform saves your history for comparison.

How do I validate report packages?

Upload the complete ZIP file. We validate both the XHTML content and the package structure (META-INF, manifest, structure).

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