IFRS Taxonomy 2026: Why There Is No Update and What That Means for Your ESEF Filing

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. 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 (FS).

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 arrived in April 2024. IFRS 19 Subsidiaries without Public Accountability followed in May 2024. Amendments to the classification and measurement of financial instruments under IFRS 9 and IFRS 7 were also issued in May 2024. Annual Improvements Volume 11 was issued in July 2024, and contracts referencing nature-dependent electricity under IFRS 9 and IFRS 7 came in December 2024.

IFRS 18 elements are the most significant addition. Two entry points are provided. The “Full IFRS Accounting Standards” entry point applies to entities using IAS 1 . An “Early Application of IFRS 18 ” entry point is available 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 and new mandatory subtotal elements (operating profit or loss, profit or loss before financing and income taxes). It also adds 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. EFRAG issued its endorsement recommendation in May 2025, but the European Commission had not finalised endorsement as of the ESMA publication date.

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 FS. Your review of the ESEF filing should confirm the correct taxonomy version, verify that mandatory mark-up elements are tagged, check that extension elements (entity-specific tags) are properly anchored to the base taxonomy, and confirm the correct entry point is used. The file should tell a story of what was tagged, why, and where each extension ended up. If a reviewer can’t trace that narrative through the working papers (WPs), the tagging probably isn’t supportable either.

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 FS) 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, so each MPM is tagged with its definition, the reconciling items, the most similar IFRS-defined subtotal, and the calculation relationship between them. This is concept matching hell on the first file you review. Expect the first few MPMs to take a reviewer an hour each before a rhythm sets in.

A further technical change is that 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 (issued in early 2026), 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, financing, and tax items, the tagging process will surface that gap at filing time. Raise this with the client during 2026 year-end planning.

Specifically, 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 (published February 2026) explicitly flags that issuers should review and deprecate any previous extension taxonomy elements to prevent duplication and ensure consistency. If your client currently tags a self-defined “operating profit” using an extension element, that element will need to be replaced with the standard IFRS 18 element in the 2027 filing.

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 FS are within acceptable tolerances. ESMA has indicated it will review technical errors (including duplicate tags, incorrect anchoring, unnecessary taxonomy extensions, and missing mandatory elements) 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 FS. 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. This is where ticking and bashing the tagged fields against the printed FS catches most review errors.

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 FS.

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

1. 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.
2. 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.
3. Check that the Calculations 1.1 specification is applied. Run the validation suite and document results.
4. Review all extension elements for proper anchoring to the base taxonomy. ESMA and national regulators are tightening review of technical errors.
5. 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.
6. 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.
• Assuming the 2025 taxonomy carries no changes from 2024. It does. The 2025 release added IFRS 18 elements, IFRS 19 elements, financial instruments amendments, and Calculations 1.1 support. Even if your client isn’t early-adopting IFRS 18 , the validation specification changed.

Related content

• ISA 520 analytical review calculator: Run analytical procedures on the tagged financial data to identify unusual movements before the ESEF filing is submitted.
• IFRS 18 presentation and disclosure in financial statements: what changes from IAS 1 and what auditors need to do: The full ciferi guide on IFRS 18 , including the worked example of reclassifying an income statement.

Related content

Related guides:

Put audit concepts into practice with these free tools:

Frequently asked questions