Key Takeaways
- Why the IFRS Foundation skipped a 2026 taxonomy release and what the 2025 taxonomy already contains
- How the ESEF 2025 taxonomy update (mandatory for EU issuers with financial years starting on or after 1 January 2026) creates a dual-track IAS 1 / IFRS 18 structure
- What the 2025 taxonomy’s IFRS 18 elements mean for early adopters vs standard-timeline entities
- What auditors should check in ESEF filings for the 2026 reporting season
What happened: no 2026 taxonomy release
The IFRS Foundation publishes the IFRS Accounting Taxonomy annually, typically in Q1. Each release reflects new or amended IFRS standards that affect taxonomy content. In February 2026, the Foundation published guidance confirming that no 2026 release was necessary. The 2025 version already reflects all IFRS standards issued up to 1 January 2025, and no further amendments required taxonomy changes for the 2026 reporting period.
This is not unusual. The Foundation has skipped updates before when the annual standards pipeline did not produce taxonomy-relevant changes. But for auditors, the practical consequence is straightforward: the 2025 taxonomy is the filing version for both the 2025 and 2026 reporting years.
The IFRS Foundation also noted that the next annual taxonomy will be published in Q1 2027. That release will be the one incorporating mandatory IFRS 18 tagging elements for all entities (not just early adopters). If your client reports on a calendar year-end, the 2027 taxonomy will apply to their first mandatory IFRS 18 financial statements.
What the 2025 taxonomy contains
The 2025 taxonomy (published March 2025) was a material update. It incorporated five sets of changes from standards issued during 2024:
- IFRS 18 Presentation and Disclosure in Financial Statements (issued April 2024)
- IFRS 19 Subsidiaries without Public Accountability (issued May 2024)
- Amendments to the classification and measurement of financial instruments under IFRS 9 and IFRS 7 (issued May 2024)
- Annual Improvements Volume 11 (issued July 2024)
- Contracts referencing nature-dependent electricity under IFRS 9 and IFRS 7 (issued December 2024)
IFRS 18 elements are the most significant addition. Two entry points are provided: the “Full IFRS Accounting Standards” entry point (for entities applying IAS 1) and an “Early Application of IFRS 18” entry point (for entities that have already adopted IFRS 18 before its mandatory effective date of 1 January 2027). The IFRS 18 entry point introduces new line-item elements for the five income and expense categories, new mandatory subtotal elements (operating profit or loss, profit or loss before financing and income taxes), and dimensional modelling for management-defined performance measure (MPM) disclosures.
The taxonomy also includes a validation formula for MPM reconciliations. This formula checks that the MPM subtotal reconciles to the most directly comparable IFRS-defined subtotal. The IFRS Foundation encouraged preparers to use this formula during the tagging process.
For entities not early-adopting IFRS 18, the 2025 taxonomy’s IAS 1 entry point is unchanged in substance from the 2024 version. You tag the same way you tagged last year.
ESEF implications for EU issuers
The ESEF (European Single Electronic Format) adds a regulatory layer on top of the IFRS taxonomy. ESMA publishes Regulatory Technical Standards (RTS) specifying which taxonomy version EU issuers must use. In September 2025, ESMA published an amendment to the ESEF RTS incorporating the 2025 IFRS taxonomy.
The 2025 ESEF taxonomy becomes mandatory for annual financial reports covering financial years starting on or after 1 January 2026. For calendar year-end entities, this means the 2026 annual report filed in 2027 must use the 2025 ESEF taxonomy. Issuers could voluntarily use the 2025 ESEF taxonomy for their 2025 annual reports if the RTS was adopted in time. ESMA also noted that IFRS 18 taxonomy elements may only be used after the standard has been formally endorsed at EU level.
For auditors in the Netherlands (and across the EU), the ESEF filing is within the scope of the statutory audit. Many EU member states now require auditors to provide assurance on the accuracy and structure of XBRL tagging, not just the underlying financial statements. Your review of the ESEF filing should confirm the correct taxonomy version, verify that mandatory mark-up elements are tagged, and check that extension elements (entity-specific tags) are properly anchored to the base taxonomy.
Documentation note
The AFM and other national competent authorities have increased their scrutiny of ESEF filings over the past two years. Common findings include missing mandatory tags, duplicate tagging of the same line item, extension elements that could have used a standard taxonomy element instead, and incorrect anchoring of extensions. If your client’s filing tool generates extension elements automatically, verify each one. Automated tools sometimes create extensions where a base taxonomy element already exists, simply because the entity’s label does not exactly match the taxonomy label. This is a tagging error, not a genuine need for an extension.
The dual-track system: IAS 1 vs IFRS 18 entry points
The 2025 taxonomy creates a two-track system that will persist through the 2026 and early 2027 filing seasons. Most entities will continue using the IAS 1 entry point. Early adopters of IFRS 18 must use the IFRS 18 entry point.
For entities on the IAS 1 track, the tagging requirements are familiar. The mandatory Table 2 mark-up elements (the elements ESMA requires to be tagged on the face of the primary financial statements) remain the same as in previous years.
For early adopters of IFRS 18, the tagging requirements change substantially:
- The IFRS 18 entry point includes restructured presentation elements for the statement of profit or loss reflecting the five categories
- The mandatory subtotals (operating profit, profit before financing and income taxes) have dedicated taxonomy elements
- ESMA noted that early adopters must use the IFRS 18 Table 2 mandatory mark-up elements rather than the IAS 1 set
ESMA also included IFRS 18 MPM tagging elements in the 2025 ESEF taxonomy. These are not yet mandatory but are included to allow issuers to familiarise themselves with MPM mark-up. The MPM taxonomy uses dimensional modelling: each MPM is tagged with its definition, the reconciling items, and the most similar IFRS-defined subtotal.
A further technical change: the 2025 ESEF taxonomy requires use of the Calculations 1.1 specification, which reduces validation inconsistencies caused by rounding. This applies to all filers, not just early adopters.
What changes in the 2027 taxonomy
The Q1 2027 taxonomy will be the big release. It will incorporate mandatory IFRS 18 elements for all entities, not just early adopters. The IAS 1 entry point will be deprecated (entities can no longer file against it for financial years starting on or after 1 January 2027). Every IFRS-reporting entity that files digitally will need to map its income statement to the new category structure.
The 2027 taxonomy will also reflect any further amendments issued during 2025 and 2026. At this stage, the most notable upcoming content is the IASB’s consultation on clarifying the fair value option under IAS 28, which addresses how entities with investment-related main business activities apply the fair value option in the context of IFRS 18 category classification.
For auditors, the 2027 taxonomy is the one that requires advance preparation. If your listed clients have not started mapping their income and expense line items to the five IFRS 18 categories, they will face a compressed timeline in 2027. The taxonomy structure determines which elements are available for tagging. If the client’s chart of accounts does not distinguish between operating, investing, and financing items, the tagging process will surface that gap at filing time. Raise this with the client during 2026 year-end planning.
Documentation note
The 2027 taxonomy will require entities to tag the new mandatory subtotals (operating profit, profit before financing and income taxes) using the dedicated IFRS 18 elements. Any existing extension elements that the entity created for self-defined operating profit under IAS 1 will need to be deprecated. ESMA’s public statement on IFRS 18 implementation (February 2026) explicitly flags this: issuers should review and deprecate any previous extension taxonomy elements to prevent duplication and ensure consistency.
Worked example: reviewing an ESEF filing for the 2026 reporting year
Client: Hoekstra Maritiem N.V., a Dutch listed shipping company with €145M revenue, reporting on a calendar year-end. Hoekstra has not early-adopted IFRS 18. The 2026 annual report will be filed in ESEF format in April 2027.
Step 1: Confirm the taxonomy version
Hoekstra is filing for a financial year starting 1 January 2026. The 2025 ESEF taxonomy is mandatory. The 2024 taxonomy is not permitted for this filing year. Confirm the filing tool is configured for the 2025 ESEF taxonomy and the Full IFRS Accounting Standards (IAS 1) entry point.
Documentation note
Record the taxonomy version in the ESEF review working paper. Reference the ESMA RTS amendment of September 2025. Confirm IAS 1 entry point is correct (Hoekstra has not early-adopted IFRS 18).
Step 2: Review the Calculations 1.1 specification
The 2025 ESEF taxonomy requires use of Calculations 1.1 for validation. Check that the filing tool applies this specification. Verify that rounding differences between tagged amounts and the filed financial statements are within acceptable tolerances. ESMA has indicated it will review technical errors (including duplicate tags, incorrect anchoring, and taxonomy extensions) more closely.
Documentation note
Run the ESEF validation suite. Record any warnings or errors. Document the resolution of each item. Flag any extension elements that require anchoring to base taxonomy elements.
Step 3: Verify mandatory mark-up
Check that all Table 2 mandatory elements are tagged in the primary financial statements. For Hoekstra, this includes revenue, profit or loss, total assets, total equity, and the other mandatory line items specified in the ESEF RTS. Confirm no mandatory element is missing or tagged to an incorrect taxonomy element.
Documentation note
Cross-reference each Table 2 mandatory element to the tagged value in the iXBRL file. Record any discrepancies. Verify that the tagged amounts agree to the audited financial statements.
Step 4: Check extension elements
Hoekstra uses an entity-specific line item “Vessel impairment losses” that does not have a direct base taxonomy match. Verify that this extension element is anchored to the closest standard element (e.g., “Impairment loss recognised in profit or loss, property, plant and equipment”) and that the anchoring is accurate.
Documentation note
List all extension elements in the filing. For each, record the anchoring target and confirm it is the closest match in the base taxonomy. Flag any extensions that could use a standard element instead.
Step 5: Assess IFRS 18 readiness for 2027
Hoekstra has not begun mapping its income statement to the five IFRS 18 categories. The 2027 filing will require the IFRS 18 entry point. Raise this with management during the 2026 completion meeting. Document in the going-forward planning memo that the 2027 ESEF filing will require remapping all income and expense tags to the new category structure.
Documentation note
Include an IFRS 18 transition flag in the planning memo. Reference the ESMA public statement on IFRS 18 implementation (February 2026), which states that ESMA and national competent authorities will monitor the level of transparency issuers provide about IFRS 18 implementation effects.
Practical checklist for your file
- Confirm the client’s ESEF filing uses the 2025 IFRS Accounting Taxonomy. The 2024 taxonomy is not permitted for financial years starting on or after 1 January 2026. There is no 2026 taxonomy.
- Verify the correct entry point. If the client has not early-adopted IFRS 18, use the Full IFRS Accounting Standards (IAS 1) entry point. If the client has early-adopted, use the Early Application of IFRS 18 entry point and verify the IFRS 18 Table 2 mandatory mark-up elements are tagged.
- Check that the Calculations 1.1 specification is applied. Run the validation suite and document results.
- Review all extension elements for proper anchoring to the base taxonomy. ESMA and national regulators are tightening review of technical errors.
- For 2027 planning: confirm whether the client has started mapping income and expense line items to the five IFRS 18 categories. If not, raise this during the 2026 completion meeting. The 2027 taxonomy will deprecate the IAS 1 entry point.
- Document the ESEF review in a standalone working paper. Record the taxonomy version, entry point, validation results, extension element assessment, and any IFRS 18 transition planning points.
Common mistakes
- Filing against the 2024 taxonomy for a 2026 reporting year. The 2025 ESEF taxonomy is mandatory for financial years starting on or after 1 January 2026. Using the prior version will trigger a rejection or review comment from the national competent authority.
- Using IFRS 18 taxonomy elements before the standard has been endorsed at EU level. ESMA explicitly stated that IFRS 18 elements may only be used after formal EU endorsement. Filing with IFRS 18 elements before endorsement creates a non-compliant filing.
- Ignoring extension element anchoring. ESMA and national regulators are increasing scrutiny of extension elements. An unanchored or poorly anchored extension undermines comparability and may generate a review inquiry.
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Frequently asked questions
Is there an IFRS Taxonomy 2026?
No. The IFRS Foundation confirmed in February 2026 that no 2026 taxonomy release was necessary. The 2025 IFRS Accounting Taxonomy remains the current version for the 2026 reporting period. The next annual taxonomy will be published in Q1 2027.
Which taxonomy version should EU issuers use for the 2026 reporting year?
EU issuers must use the 2025 ESEF taxonomy for annual financial reports covering financial years starting on or after 1 January 2026. The 2024 taxonomy is not permitted for this filing year. Use the Full IFRS Accounting Standards (IAS 1) entry point unless the entity has early-adopted IFRS 18.
What changes in the 2027 IFRS taxonomy?
The Q1 2027 taxonomy will incorporate mandatory IFRS 18 elements for all entities. The IAS 1 entry point will be deprecated. Every IFRS-reporting entity that files digitally will need to map its income statement to the new five-category structure (operating, investing, financing, income taxes, discontinued operations).
Can EU issuers use IFRS 18 taxonomy elements before formal EU endorsement?
No. ESMA explicitly stated that IFRS 18 taxonomy elements may only be used after the standard has been formally endorsed at EU level. Filing with IFRS 18 elements before endorsement creates a non-compliant filing.