Build ESEF iXBRL Annual Report (Czech issuers)
Skill: Convert a consolidated IFRS annual report into ESEF Inline XBRL
Region: Czech Republic (Česká republika) Category: Financial statements — ESEF disclosure Does: Takes a listed issuer's consolidated IFRS annual report and tags it as ESEF Inline XBRL (XHTML + embedded XBRL) — the EU Single Electronic Format — for disclosure (filed with the issuer's home regulator / ČNB supervision and the regulated-market storage mechanism). Spec: ESEF Regulatory Technical Standards (Commission Delegated Regulation 2019/815) — Inline XBRL + the ESEF taxonomy (IFRS-based, annual release)
ESEF is mandatory across the EU for issuers on regulated markets preparing consolidated IFRS statements: the annual financial report is an XHTML document with the primary financial statements tagged in Inline XBRL and (progressively) the notes block-tagged. The ESEF taxonomy extends the IFRS Taxonomy and is updated annually. This is an EU-wide pattern — the same skill applies to other regulated markets (NBS/SK, MNB/HU) with the issuer's home-state filing channel.
When this applies
- An issuer whose securities trade on an EU regulated market and that prepares consolidated accounts under IFRS files its Annual Financial Report in ESEF.
- Single (non-consolidated) statements may be in XHTML without full tagging; consolidated IFRS statements require iXBRL tagging.
Tagging requirements
XHTML document the full annual financial report, human-readable
Inline XBRL facts:
Primary statements statement of financial position, P&L / OCI, cash flows, changes in equity
→ each line item tagged to an IFRS/ESEF element
Notes (block tagging) defined sections of the notes tagged as text blocks
Entity & period contexts (period instant/duration + entity LEI)
Units iso4217 currency; shares; per-share
Extensions issuer-specific elements anchored to the ESEF/IFRS core
Tagging rules
- Use the IFRS/ESEF taxonomy element for each primary-statement line; where no core element fits, create an extension element and anchor it to the closest wider/narrower core concept (anchoring is mandatory under ESEF).
- Mark up the primary statements at line-item granularity; block-tag the notes for the periods where note tagging applies.
- Every fact needs a context (period + entity LEI), and numeric facts need a unit and decimals/scale; displayed values reconcile to tagged values.
- Sign/format conventions: use the correct sign and the calculation linkbase so subtotals/totals foot.
- Validate with an ESEF/Arelle validator (and the issuer's filing-platform rules) — common errors are missing anchoring, wrong taxonomy year, and context/unit mistakes.
Worked example (one fact, inline)
<!-- Total assets of CZK 5,250 thousand at 31 Dec 2025 (consolidated) -->
<ix:nonFraction
name="ifrs-full:Assets"
contextRef="c-2025-12-31" <!-- instant; entity LEI context -->
unitRef="czk"
decimals="-3"
scale="3"
format="ixt:num-dot-decimal">5,250</ix:nonFraction>
<!-- tagged value = 5,250 × 10^3 = CZK 5,250,000 -->
With the entity LEI + period contexts and CZK unit declared in the iXBRL header; the XHTML renders the full report.
Validation checklist
- Issuer in scope (EU regulated market, consolidated IFRS); current-year ESEF/IFRS taxonomy used
- Primary statements tagged at line-item level; notes block-tagged where required
- Extension elements anchored to core IFRS/ESEF concepts (mandatory)
- Every fact has a context (period + entity LEI); numeric facts have unit + decimals/scale; values reconcile
- Calculation linkbase foots (components → subtotals/totals); signs correct
- XHTML is a faithful rendering of the annual report
- Passes ESEF/Arelle validation and the home-regulator filing-platform checks before submission
Last updated: 2026-05-31 — the ESEF/IFRS taxonomy and note-tagging scope update annually; confirm the current taxonomy year, anchoring and block-tagging requirements, and the home-state (ČNB) filing channel against current ESMA ESEF and ČNB guidance before filing.