KHT / HT Auditors · ISAE 3000 · In force December 2023
Since December 2023, Finnish issuers' auditors must audit or provide ISAE 3000 assurance on ESEF financial statements. XBRTags produces the mapping walkthroughs, anchoring reports and tag reconciliation that KHT and HT firms need to complete their engagement — formatted for your audit tools.
Dec 2023
Securities Markets Act amendment in force
ISAE 3000
Assurance standard covering all three layers
24-48 hr
Fast-track option during audit season
KHT & HT
Both auditor types covered under one engagement
The Requirement
Finnish Securities Markets Act · Amendment 21 December 2023 · Law 1260/2023
Full legal background →Under the December 2023 amendment, an issuer's auditor — KHT or HT — must either audit the ESEF financial statements or perform an ISAE 3000 assurance engagement covering the human-readable layer, the machine-readable XBRL layer, and the accuracy of taxonomy mapping including extension element anchoring.
This means the iXBRL file must be audit-grade — not just technically valid. Every tagging decision must be documented, every anchoring choice must be defensible, and the file must be fully consistent across both layers. A file that passes ESMA validation rules but has incorrect tag selections or incomplete anchoring documentation will create problems during your ISAE 3000 review.
01
The financial statements as they appear to the reader in a browser or PDF. Must be consistent with the audited accounts and contain no material differences from the version shareholders receive.
02
The XBRL data embedded in the iXBRL file. Every tagged value must be consistent with the corresponding figure in the human-readable layer. Calculation relationships must reconcile correctly across the taxonomy.
03
Every XBRL tag must correctly represent the financial concept it labels. Extension elements must be anchored to the nearest base taxonomy concept. Anchoring must be traceable and documented for auditor review.
What XBRTags Delivers for Auditors
Mapping walkthrough
Every tagging decision explained — concept selection, extension rationale, scope boundaries
A complete document explaining every tagging decision in the iXBRL file — which ESMA taxonomy concept was chosen for each line item, why an extension was created where no standard concept fitted, and how each figure in the financial statements is represented in the XBRL data layer. Cross-referenced to the ESMA taxonomy documentation and relevant IFRS guidance. Structured to support your ISAE 3000 review procedures without requiring you to interpret raw XBRL files.
Anchoring review report
Extension elements, base taxonomy anchors, anchoring rationale
Detailed documentation of every extension element created in the iXBRL file — its definition, the ESMA base taxonomy concept it is anchored to, and the rationale for the anchoring choice. Structured to support your review of anchoring completeness and appropriateness, in accordance with the ESMA ESEF Regulation and related Q&A guidance. Includes an index of all extensions for rapid cross-referencing during your engagement.
Tag-level reconciliation
XBRL values matched to human-readable statements, layer consistency
A structured reconciliation table matching every XBRL-tagged value to the corresponding line item in the human-readable financial statements. Supports your consistency check across both layers of the iXBRL file. Formatted as a spreadsheet for direct import into your audit working paper tools — no reformatting required.
Blocking-error pre-check
ESMA validation rules, Nasdaq CSF test submission, clean file before delivery
Before any file leaves our workflow, we run a full validation pass against ESMA's complete error and warning rule set using the Arelle validation engine, and test-submit against Nasdaq Helsinki CSF. Every blocking error is resolved before you receive the file. You receive a clean, portal-ready iXBRL file with a validation summary — no surprises during your assurance review.
Working papers
Formatted for direct use in standard audit tools — no reformatting
All documentation — mapping walkthrough, anchoring report, reconciliation — delivered in formats compatible with standard audit working paper tools. Your team can incorporate them directly into your existing audit file structure without manual reformatting. We adapt the format to your firm's preferred structure on request.
Audit Season Fast-Track
Finnish ESEF filings concentrate in January-March. For audit firms with multiple listed clients, the overlap between engagement deadlines and assurance documentation demands can be acute. XBRTags offers a dedicated fast-track for audit season — 24-48 hour delivery with extended hours and weekend availability.
24-48 hour delivery
Full ESEF tagging, Nasdaq CSF validation and all assurance documentation within one to two business days.
Evening and weekend availability
When your client's filing is due Monday, your XBRTags specialist works through the weekend to deliver Friday.
Re-documentation of third-party files
If your client's iXBRL was prepared by another provider and lacks adequate assurance documentation, we review and re-document — or re-tag — within the same timeline.
Auditor Feedback
Jari N.
KHT Partner, Helsinki audit practice
"The mapping walkthrough XBRTags provides is exactly what we need for the ISAE 3000 engagement. Every tagging decision is explained with a reference to the ESMA guidance. Our review time dropped significantly compared to when clients used software and produced their own documentation."
Laura R.
Senior Audit Manager, Big 4 Helsinki office
"We had three listed clients with ESEF filings due in the same two-week window. XBRTags fast-tracked all three. The tag reconciliation documents came pre-formatted for our working paper system. That saved our team two full days of rework during peak audit season."
Markus K.
Director of Assurance, regional audit firm
"One client's iXBRL had anchoring issues we couldn't easily trace. We switched to XBRTags mid-engagement. They produced a full re-tag with corrected anchoring and documentation within 48 hours. The ISAE 3000 engagement completed without further queries."
FAQ
Under the Finnish Securities Markets Act amendment of 21 December 2023, an issuer's KHT or HT auditor must audit or perform ISAE 3000 assurance on: (1) the human-readable financial statements and their consistency with the audited accounts; (2) the machine-readable XBRL data layer and its consistency with the human-readable layer; and (3) the accuracy of taxonomy mapping including anchoring of extension elements. All three layers must be addressed in the assurance opinion.
No. XBRTags produces the iXBRL file and the technical documentation that supports the auditor's ISAE 3000 engagement. The assurance engagement itself — including the assurance opinion — is performed and signed by the KHT or HT auditor. Our role is to produce output of audit-grade quality, documented to support your engagement procedures.
Yes. If your client's ESEF iXBRL was prepared by a software tool or another provider and lacks adequate assurance documentation — or has anchoring issues you cannot easily trace — XBRTags can review the file, produce a mapping walkthrough and anchoring report, and re-tag elements if required. Contact us with the file for a scope assessment within one business hour.
For tight audit deadlines we offer a 24-48 hour fast-track option including full ESEF tagging, Nasdaq CSF validation and all assurance documentation. We offer extended hours and weekend delivery during the January-March peak season. Contact us with your deadline to confirm availability and scope.
For Digital Assurance Support engagements we recommend a brief scope confirmation covering deliverables, timeline, confidentiality and fee. All client data is handled under ISO 27001-certified processes with confidentiality agreements signed by all specialists. Contact us to discuss your preferred engagement structure.
Tell us your client's filing deadline and we confirm scope and deliverables within one business hour. Fast-track 24-48 hour delivery available during audit season.
+ 31 (10) 8906661 · hello@xbrtags.fi · Mon-Fri 09:00-18:00 GMT