How do effective dates work?
- IFRS: a standard or amendment applies to annual reporting periods beginning on or after a stated date, usually 1 January, with earlier application often permitted. Each jurisdiction adopts IFRS in its own way, so the date a company must apply a new standard can depend on local endorsement, such as by the EU or the UK Endorsement Board.
- US GAAP: an Accounting Standards Update applies to fiscal years beginning after 15 December of a year, which for a calendar year company means the next January. Public business entities usually go first and other entities, including private companies and many not-for-profits, a year later.
- Comparatives: a standard applied retrospectively, such as IFRS 18, needs the comparative year restated, so the data must be collected from the start of the year before the effective date.
The timeline at a glance
IFRS: what applies when?
| Standard | What it changes | First December year end | Note |
|---|---|---|---|
| Amendments to IFRS 9 and IFRS 7: classification and measurement | Settling liabilities by electronic payment, ESG-linked loan features, new disclosures | 2026 | In force |
| Amendments to IFRS 9 and IFRS 7: nature-dependent electricity | Own-use and hedge accounting for renewable power purchase agreements | 2026 | In force |
| Annual Improvements, Volume 11 | Small fixes to IFRS 1, 7, 9 and 10 and IAS 7 | 2026 | In force |
| IFRS 18 Presentation and Disclosure in Financial Statements | Replaces IAS 1: operating, investing and financing categories, operating profit, management-defined performance measures | 2027 | Retrospective, so 2026 comparatives are restated |
| IFRS 19 Subsidiaries without Public Accountability: Disclosures | Reduced disclosures for eligible subsidiaries | 2027 | Optional |
| Amendments to IAS 21: hyperinflationary presentation currency | Translation into a presentation currency that is hyperinflationary | 2027 | |
| Amendments to IAS 28: fair value option | Which investors may measure associates at fair value | 2027 | Applied with IFRS 18 |
| IFRS for SMEs, third edition | Revenue, fair value, financial instruments, control and business combinations | 2027 | For entities without public accountability |
| IFRS 20 Regulatory Assets and Regulatory Liabilities | Regulatory assets and liabilities for rate-regulated businesses; replaces IFRS 14 | 2029 | Issued May 2026 |
| Revised IAS 28 Investments in Associates and Joint Ventures | Answers to common equity method questions | 2029, expected | Expected to be issued in 2027 |
The IASB is also working on provisions under IAS 37, business combinations disclosures and goodwill, amortised cost measurement, financial instruments with characteristics of equity and a risk mitigation accounting model, none of which has an effective date yet. Sustainability reporting has its own dates: the amendments to IFRS S2 issued in December 2025 apply from 1 January 2027, and when IFRS S1 and S2 become mandatory depends on each jurisdiction. See the IFRS S2 amendments and ISSB adoption by country.
US GAAP: what applies when?
| Update | What it changes | Public business entities | Other entities |
|---|---|---|---|
| ASU 2023-09 Income tax disclosures | Rate reconciliation categories and income taxes paid by jurisdiction | 2025 | 2026 |
| ASU 2025-05 Credit losses on current receivables | A practical expedient for current receivables and contract assets | 2026 | 2026 |
| ASU 2024-03 Disaggregation of income statement expenses | Expense captions broken down into purchases of inventory, employee pay, depreciation and more | 2027, interim 2028 | Not required |
| ASU 2025-07 Derivatives scope refinements | Contracts based on a party's own operations taken out of ASC 815 | 2027 | 2027 |
| ASU 2025-09 Hedge accounting improvements | Groups of forecasted transactions, choose-your-rate debt, nonfinancial components | 2027 | 2028 |
| ASU 2025-06 Internal-use software | Removes the project stages for capitalizing software costs | 2028 | 2028 |
| ASU 2025-11 Interim reporting | Interim disclosures gathered in ASC 270, with a disclosure principle | 2028 | 2029 |
| ASU 2026-02 Environmental credits | Recognition of credits and compliance obligations in a new Topic 818 | 2028 | 2029 |
| ASU 2026-03 Contractual sale restrictions | Investment companies reflect lockups in fair value | 2028 | 2028 |
| ASU 2025-10 Government grants | Recognition of grants received by business entities in Topic 832 | 2029 | 2030 |
Years are the first calendar fiscal year the update applies to; early adoption is permitted for most. ASU 2024-03 applies only to public business entities. The FASB is working on further projects, such as the equity method and the classification of debt with subjective acceleration clauses, with exposure drafts expected in late 2026.
In practice: what a December year end company does when
| When | IFRS reporter | US public company |
|---|---|---|
| 1 January 2026 | Starts collecting income and expenses in the IFRS 18 categories, because 2026 will be the restated comparative year | Applies ASU 2025-05; prepares for ASU 2024-03 expense disaggregation |
| 31 December 2026 | Applies the IFRS 9 and IFRS 7 amendments for the first time; discloses the expected effect of IFRS 18 | Second year of ASU 2023-09 tax disclosures |
| 31 March 2027 | First interim report under IFRS 18, reconciling the comparative quarter | Applies ASU 2025-07 and ASU 2025-09 from the start of the year |
| 31 December 2027 | First annual statements under IFRS 18, with 2026 restated; IFRS 19 available for subsidiaries | First annual DISE disclosures in the Form 10-K |
| 2028 | Prepares for IFRS 20 if rate-regulated | DISE in quarterly reports; ASU 2025-06, ASU 2025-11 and ASU 2026-02 apply |
| 2029 | IFRS 20 and the expected revised IAS 28 apply | ASU 2025-10 on government grants applies |
See IFRS 18 transition and comparatives, the IFRS 18 implementation checklist and IFRS 18 vs the US GAAP income statement.
Where to read more on each change
- IFRS 18 explained and IFRS 19 reduced disclosures
- Regulatory deferral accounts and IFRS 20 and IFRS 11 and IAS 28
- IFRS for SMEs explained and IAS 21 lack of exchangeability
- ASU 2023-09 income tax disclosures, ASC 815 and ASU 2025-09 and IAS 20 vs US GAAP and ASU 2025-10
- IAS 34 vs ASC 270 and ASU 2025-11
Keep going
Our free Excel models work through the examples in these guides, and the comparisons show where IFRS and US GAAP part ways. Every guide names the Chartered Accountant who wrote it and the one who reviewed it.
Questions people ask
When is IFRS 18 effective?
For annual reporting periods beginning on or after 1 January 2027, applied retrospectively, so a December year end company restates its 2026 comparatives.
When does ASU 2024-03 apply?
To public business entities for annual periods beginning after 15 December 2026 and interim periods beginning after 15 December 2027, so 2027 annual and 2028 quarterly reports for a calendar year company.
When does IFRS 20 apply?
For annual periods beginning on or after 1 January 2029, with earlier application permitted.
Do private companies get more time under US GAAP?
Usually. Many updates, such as ASU 2025-09, ASU 2025-10 and ASU 2025-11, apply to entities other than public business entities a year later.
Sources
The standards, updates and other documents this guide draws on.
- EY: IFRS Update of standards and interpretations in issue at 30 June 2026
- IFRS Foundation: IFRS 18 Presentation and Disclosure in Financial Statements
- IFRS Foundation: Rate-regulated activities project, IFRS 20 Regulatory Assets and Regulatory Liabilities
- Financial Accounting Standards Board
- BDO USA: FASB finalizes ASU to disaggregate income statement expenses (DISE)
- Crowe: FASB issues final ASU on government grants for businesses (ASU 2025-10)
- Stout: ASU 2025-11, interim financial reporting
Rules and fees change. If you are reading this long after October 26, 2026, confirm the figures with the source before you rely on them.
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This guide is general information. It is not tax or legal advice for your situation.