Quality ESEF tagging requires more than just mapping numbers to concepts. This guide shares best practices developed from thousands of ESEF filings to help you produce accurate, consistent, and audit-ready tagged reports.
Key Takeaways
- Start with a complete mapping before tagging
- Use consistent tagging patterns across periods
- Document all tagging decisions
- Validate incrementally, not just at the end
- Maintain a reusable tagging template
Planning Your Tagging
Before starting to tag:
1. Review previous year's tagging (if applicable)
2. Identify new disclosure requirements
3. Map all items to taxonomy elements
4. Plan extension elements needed
5. Set up validation workflow
A well-planned approach prevents rework and ensures consistency.
Element Selection
Choosing the right element:
• Match semantic meaning, not just label
• Consider element type (monetary, text, etc.)
• Check period type (instant vs duration)
• Verify dimensional requirements
• Review element documentation
When multiple elements could apply, choose the most specific one that accurately represents your disclosure.
Context and Units
Context and unit consistency:
• Reuse context IDs where appropriate
• Use ISO currency codes for units
• Apply correct decimals precision
• Maintain period consistency
• Handle segment reporting dimensions
Inconsistent contexts create duplicate facts and calculation issues.
Consistency Across Periods
For comparatives: Use identical element selections year-over-year unless there's a good reason to change. Document any tagging changes with explanations. Consider creating a tagging mapping document that persists across periods.
Documentation
Document your tagging process:
• Element selection rationale
• Extension justifications
• Anchoring decisions
• Known limitations
• Audit responses
Good documentation speeds up future filings and supports audit inquiries.
Checklist
- Create tagging mapping document
- Review base taxonomy for matches
- Document extension rationale
- Verify context consistency
- Check unit definitions
- Validate incrementally
- Prepare audit documentation