December 2026 is when everything changes. ISA 240 (Revised), ISA 570 (Revised 2024), ISSA 5000, and the narrow-scope amendments to the listed entity and PIE definitions all share the same effective date: periods beginning on or after 15 December 2026. For calendar year-end clients, that means the 2027 audit. If your firm hasn’t started implementation planning, you’re behind. In our experience, most mid-tier firms underestimate how much methodology, template, and training work this triggers.

This tracker covers every ISA, ISQM, ISSA, and ISAE standard currently in effect or approved with a future effective date, as issued by the IAASB through early 2026. ISA 240 (Revised) and ISA 570 (Revised 2024) are effective for audits of financial statements for periods beginning on or after 15 December 2026, and the IAASB encourages jurisdictions to adopt both standards together because they were drafted as a coordinated package.

Key takeaways

  • Which standards are currently effective and which have upcoming effective dates you need to plan for
  • What ISA 240 (Revised) and ISA 570 (Revised 2024) change in practice, not just in the standard text
  • How ISSA 5000 fits alongside the ISAs for firms performing sustainability assurance
  • What the ISA 500 series revision project means for your medium-term methodology planning

Standards currently in effect

The following standards govern current audit engagements. Unless your national standard-setter has adopted a different effective date, these apply now.

Quality management

ISQM 1 (effective 15 December 2022) governs the firm’s system of quality management. ISQM 2 (same effective date) covers engagement quality reviews. Both replaced ISQC 1.

Risk assessment

ISA 315 (Revised 2019) has been effective since 15 December 2021. It introduced the spectrum of inherent risk factors and required a more granular assessment of risks of material misstatement at the assertion level. This is the standard that currently governs your risk assessment procedures. No further revision is expected until the ISA 500 series project touches ISA 330 (risk responses) and ISA 520 (analytical procedures).

Other current standards

ISA 220 (Revised) on quality management at the engagement level is effective for audits of periods beginning on or after 15 December 2022, aligned with the ISQM 1 effective date. The remaining ISAs ( ISA 200 , ISA 230 , ISA 250 , ISA 260 , ISA 265 , ISA 300 , ISA 320 , ISA 330 , ISA 402 , ISA 450 , ISA 500 , ISA 501 , ISA 505 , ISA 510 , ISA 520 , ISA 530 , ISA 540 (Revised), ISA 550 , ISA 560 , ISA 580 , ISA 600 (Revised), ISA 610 , ISA 620 , ISA 700 series, ISA 800 series, ISA 805 , ISA 810 ) remain in their current versions until amended by future projects.

For ISA paragraph references on specific requirements within any of these standards, the ciferi.com ISA glossary covers the most-cited paragraphs for mid-tier practitioners.

The December 2026 package

Four separate IAASB projects converge on the same effective date: periods beginning on or after 15 December 2026 (meaning 2027 calendar year-end audits). The IAASB deliberately aligned these dates because the changes interact.

ISA 240 (Revised)

Approved July 2025. Overhauls the auditor’s fraud responsibilities with a fraud lens applied to the entire risk assessment process.

ISA 570 (Revised 2024)

Approved April 2025. Requires a gross assessment of going concern events and conditions before considering management’s mitigating plans.

ISSA 5000

Approved December 2024, issued January 2025. The first standalone sustainability assurance standard, replacing ISAE 3410 for greenhouse gas engagements and sitting alongside (not within) ISAE 3000 (Revised).

Narrow-scope amendments (listed entity/PIE definitions)

Approved June 2025. Replace the “listed entity” definition with “publicly traded entity” (PTE) across all ISQMs and ISAs. Align with the IESBA Code. The IAASB decided not to adopt the IESBA’s PIE definition at this time.

Narrow-scope amendments (external expert)

Issued January 2026 after PIOB certification. Amend ISAE 3000 (Revised) and ISRS 4400 (Revised) to align with IESBA Code provisions on using the work of an external expert. Effective 15 December 2026 for other assurance and related services engagements.

ISA 240 (Revised): what changes in practice

The most significant change is the removal of the presumption that records are genuine unless there is reason to believe otherwise. Under the current ISA 240 , auditors could accept records as authentic in the absence of a specific red flag. The revised standard removes this entirely. You are now expected to investigate conditions suggesting a record may not be authentic.

ISA 240 (Revised) also strengthens the fraud lens in the risk assessment process, aligning with ISA 315 (Revised 2019). The auditor must identify and assess risks of material misstatement due to fraud with the same granularity applied to other risks. For publicly traded entities, the revised standard requires additional disclosures in the auditor’s report about the auditor’s fraud-related work.

Early adoption is permitted. The IAASB encourages adopting ISA 240 (Revised) and ISA 570 (Revised 2024) together because fraud and financial distress are interrelated risks. A going concern event may be the first visible signal of fraud, and a fraud may create the conditions that trigger going concern doubt.

For firms that use the ISA 240 fraud risk assessment templates, the working papers will need updating to reflect the revised requirements once your jurisdiction adopts the standard.

ISA 570 (Revised 2024): the gross assessment shift

Under the current ISA 570 , most audit teams evaluate management’s mitigating plans alongside the events and conditions that raise going concern doubt. The revised standard separates these steps. You identify every event or condition on a gross basis first, before any mitigation. Then you evaluate whether management’s plans are feasible and sufficient.

ISA 570 (Revised 2024) also requires the auditor to report on management’s going concern assessment in all cases, not just when material uncertainty exists. The auditor’s report will include a new section on going concern for every engagement, regardless of whether a material uncertainty was identified.

This changes the structure of the going concern working paper. The current format at most mid-tier firms merges the identification and mitigation assessment into a single matrix. Under the revised standard, that structure won’t hold. The file needs two distinct steps: gross identification, then mitigation evaluation.

The practical consequence is that more entities will have events or conditions identified on a gross basis, because mitigating factors won’t offset them at the identification stage. This doesn’t automatically mean more modified opinions. It means more documentation and more engagement partner judgement on whether management’s plans are sufficient. The file should tell a story about how the team got from a gross list of indicators to a comfortable conclusion. Nobody enjoys writing that section, but skipping the gross-basis step is exactly how files get flagged on inspection. For firms without a dedicated going concern template that separates these steps, the ISA 570 going concern checklist on ciferi.com provides the structure. An updated version reflecting the revised standard will be available before the effective date.

ISSA 5000: sustainability assurance arrives

ISSA 5000 is the IAASB’s first dedicated sustainability assurance standard. It covers both reasonable and limited assurance engagements on sustainability information prepared under any reporting framework (including ESRS, GRI, ISSB, TCFD, and others). Once effective, it replaces ISAE 3410 for greenhouse gas engagements.

ISSA 5000 is a standalone standard. Unlike ISAE 3402 or ISAE 3410, practitioners performing sustainability assurance under ISSA 5000 do not also need to apply ISAE 3000 (Revised). ISAE 3000 (Revised) continues to apply for all non-sustainability assurance engagements.

For European firms, the timing aligns with the CSRD assurance requirement. Companies in CSRD scope must have their sustainability reports assured, and ISSA 5000 provides the international framework for that assurance. Whether your jurisdiction mandates ISSA 5000 or permits national standards during a transition period depends on the country-level CSRD transposition (see the CSRD implementation tracker for country-by-country status).

Standards in development

ISA 500 series revision

The IAASB is revising ISA 500 (audit evidence) and ISA 520 (analytical procedures) as a single project, with ISA 330 (risk responses) also in scope. The first full draft of all proposed revisions was scheduled for discussion at the March 2026 meeting. This project will change how auditors design and perform substantive procedures. No effective date has been set; expect a multi-year timeline from exposure draft through final standard. The project also includes conforming amendments to other ISAs where those standards reference the in-scope standards.

ISA for LCE (Less Complex Entities) maintenance

The IAASB approved the first maintenance project for the ISA for LCE in December 2025, triggered by the ISA 240 and ISA 570 revisions. A first full draft of the proposed revised ISA for LCE was scheduled for the March 2026 meeting. The ISA for LCE itself has been available since adoption in December 2023, but national adoption varies. The EU has not adopted the ISA for LCE, and there is no indication that this position will change in the short term. Firms in jurisdictions that have adopted the ISA for LCE should monitor this maintenance project closely because the revised ISA for LCE will need to reflect the new fraud and going concern requirements in a way that is proportionate for less complex audits.

National adoption: timing varies by jurisdiction

The IAASB sets international effective dates, but national standard-setters determine when (and whether) each revised standard applies in their jurisdiction.

United Kingdom

The FRC published a consultation on proposed revisions to ISA (UK) 240 and ISA (UK) 570 to align with the international revisions. The consultation closed on 16 January 2026. When finalised, both UK standards will take effect for audits of financial statements for periods beginning on or after 15 December 2026, matching the international timeline. UK firms should not assume final UK adoption until the FRC issues the final standards.

Netherlands

The NBA adopts ISAs for use in the Netherlands. The timeline for formal adoption of the revised ISA 240 and ISA 570 has not been publicly announced as of early 2026, but Dutch firms should plan on the international effective date as the baseline.

EU-wide

The European Commission has not endorsed revised ISAs at EU level since the adoption of ISA 315 (Revised 2019). The interaction between national adoption and EU-level endorsement adds complexity for firms operating across multiple Member States. The safest approach is to plan implementation based on the international effective date and adjust if your jurisdiction deviates.

Worked example: mapping the timeline onto a firm’s audit portfolio

Dekker & Vos Accountants B.V. is a Dutch non-PIE firm with 80 statutory audit clients. All are calendar year-end (31 December). The firm also has four CSRD assurance engagements starting from the 2025 reporting year.

1. Current cycle (2025 audits, opinions issued in 2026)

All 80 engagements fall under current ISAs. No action required for ISA 240 (Revised) or ISA 570 (Revised 2024). Existing methodology applies.

Documentation note: Record in the firm’s quality management monitoring file that the current ISA versions apply. Note the upcoming December 2026 effective date in the planning for methodology updates.

2. Next cycle (2026 audits, opinions issued in 2027)

Periods beginning on or after 15 December 2026 means the 2027 financial year, not 2026. For Dekker & Vos’s clients with 1 January to 31 December financial years, ISA 240 (Revised) and ISA 570 (Revised 2024) apply to the audit of the 2027 financial statements. The 2026 audit (opinion issued spring 2027) still uses the current standards.

Documentation note: The firm has 18 months from March 2026 to update its audit methodology, templates, training programmes, and internal guidance for the revised standards. Plan the methodology update for completion by September 2027, with pilot testing on early-reporting clients.

3. CSRD assurance engagements

ISSA 5000 is effective for sustainability information reported for periods beginning on or after 15 December 2026. For Dekker & Vos’s four CSRD clients reporting on calendar year 2027, ISSA 5000 applies. For their 2025 and 2026 sustainability reports, the firm applies ISAE 3000 (Revised) or national standards as permitted by the Dutch CSRD transposition.

Documentation note: Map each CSRD engagement to the applicable standard based on the reporting period. For 2025 and 2026 reports, document which standard is being applied and confirm it’s permitted under the applicable national transposition.

A reviewer would see a firm that has mapped every engagement to the correct standard version with documented implementation milestones.

Practical checklist

  1. Confirm which ISA versions your national standard-setter has adopted. The IAASB effective dates apply unless your jurisdiction has set different dates (the FRC is currently consulting on adoption of ISA (UK) 240 and ISA (UK) 570, with a consultation closing date of 16 January 2026)
  2. Map your entire audit portfolio by financial year-end to determine which engagement cycle first falls under ISA 240 (Revised) and ISA 570 (Revised 2024). For most calendar year-end clients, this is the 2027 audit
  3. Update your going concern working paper template to separate the gross identification of events and conditions from the evaluation of management’s mitigating plans ( ISA 570 (Revised 2024))
  4. Review your ISA 240 methodology to remove any reliance on the presumption that records are genuine unless flagged. Build in procedures to investigate conditions suggesting records may not be authentic
  5. If your firm performs or plans to perform sustainability assurance, determine whether ISSA 5000 or a national standard applies to your engagements based on reporting period and jurisdiction
  6. Monitor the ISA 500 series revision project for exposure drafts. When published, assess the impact on your substantive testing methodology

Common mistakes

  • Assuming ISA 240 (Revised) and ISA 570 (Revised 2024) apply to 2026 audits. They don’t. The effective date is periods beginning on or after 15 December 2026, which means the first affected financial year for calendar year-end clients is 2027 (IAASB effective date guidance). Applying the revised standards a year early isn’t wrong (early adoption is permitted), but applying them without realising you’re early is a methodology control failure.
  • Treating ISSA 5000 as an extension of ISAE 3000 (Revised). ISSA 5000 is standalone. Practitioners performing sustainability assurance under ISSA 5000 do not also apply ISAE 3000 (Revised) to the same engagement.
  • Glossary: Going concern for the ISA 570 requirements and what changes under ISA 570 (Revised 2024)
  • ISA 240 fraud risk assessment templates for structured fraud documentation under the current standard (update planned for revised standard adoption)

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Frequently asked questions

When do ISA 240 (Revised) and ISA 570 (Revised 2024) become effective?

Both standards are effective for audits of financial statements for periods beginning on or after 15 December 2026. For calendar year-end clients, this means the 2027 financial year audit. The 2026 audit (opinion issued in spring 2027) still uses the current standards. Early adoption is permitted, and the IAASB encourages adopting both standards together.

What is the main change in ISA 240 (Revised)?

The most significant change is the removal of the presumption that records are genuine unless there is reason to believe otherwise. Under the revised standard, auditors must investigate conditions suggesting a record may not be authentic. The standard also strengthens the fraud lens in the risk assessment process and requires additional disclosures for publicly traded entities.

Is ISSA 5000 part of ISAE 3000?

No. ISSA 5000 is a standalone standard. Unlike ISAE 3402 or ISAE 3410, practitioners performing sustainability assurance under ISSA 5000 do not also need to apply ISAE 3000 (Revised). ISAE 3000 (Revised) continues to apply for all non-sustainability assurance engagements.

What changes under ISA 570 (Revised 2024)?

ISA 570 (Revised 2024) requires a gross assessment of going concern events and conditions before considering management's mitigating plans. The auditor must also report on management's going concern assessment in all cases, not just when material uncertainty exists. This changes the structure of the going concern working paper, requiring two distinct steps: gross identification, then mitigation evaluation.

What is the ISA 500 series revision project?

The IAASB is revising ISA 500 (audit evidence) and ISA 520 (analytical procedures) as a single project, with ISA 330 (risk responses) also in scope. The first full draft was scheduled for discussion at the March 2026 meeting. No effective date has been set. This project will change how auditors design and perform substantive procedures.

Do ISA 240 (Revised) and ISA 570 (Revised 2024) apply to 2026 audits?

No. The effective date is periods beginning on or after 15 December 2026, which means the first affected financial year for calendar year-end clients is 2027. Applying the revised standards a year early is permitted (early adoption), but the current standards apply to 2026 audits unless your jurisdiction has set different dates.

Further reading and source references

  • IAASB project pages: The authoritative source for each standard's project timeline, exposure drafts, basis for conclusions, board minutes, and final pronouncements.
  • ISA 240 (Revised): Approved July 2025. Effective 15 December 2026. Fraud lens, record authenticity presumption removed, enhanced reporting for publicly traded entities.
  • ISA 570 (Revised 2024): Approved April 2025. Effective 15 December 2026. Gross assessment, mandatory going concern reporting, alignment with ISA 240 (Revised).
  • ISSA 5000: Approved December 2024, issued January 2025. Effective 15 December 2026. Standalone sustainability assurance standard.
  • ISA 500 series project: ISA 330 , ISA 500 , ISA 520 revision. First full draft scheduled for March 2026 meeting. No effective date set.
  • ISA for LCE maintenance: First maintenance project approved December 2025. Triggered by ISA 240 and ISA 570 revisions.