Key Points
- The ISAs are numbered from ISA 200 to ISA 810 and organised into six groups covering engagement acceptance through reporting.
- ISA 240 (Revised) and ISA 570 (Revised 2024) take effect for periods beginning on or after 15 December 2026, making them the most significant pending changes to the suite.
- National adoption varies: some jurisdictions adopt ISAs directly, while others (the Netherlands, Germany, the UK, France) issue local equivalents with additional requirements.
- An engagement that claims ISA compliance must comply with every ISA relevant to the audit; cherry-picking is not permitted.
What is International Standards on Auditing: Complete List & Status?
The IAASB organises the ISAs around the audit workflow. The 200 series covers general principles: engagement terms, quality management, documentation, fraud, and communication with governance. The 300 series addresses planning, materiality, risk assessment, and responses to assessed risks. ISA 500 through ISA 580 governs audit evidence, from sampling and analytical procedures to written representations. ISA 540 (Revised) handles accounting estimates. The 600 series covers group audits. The 700 series deals with opinion formation, modifications, emphasis of matter paragraphs, and key audit matters. The 800 series addresses special-purpose frameworks.
ISA 200.18 requires compliance with all ISAs relevant to the engagement. If a standard applies, its requirements are mandatory unless the entire standard is not relevant (ISA 200.22) or a specific requirement contains a conditional phrase the engagement does not trigger.
Complete list of ISAs (2025 handbook)
| ISA | Title | Current version | Status |
|---|---|---|---|
| 200 | Overall Objectives of the Independent Auditor | Redrafted 2009 | Effective |
| 210 | Agreeing the Terms of Audit Engagements | Revised 2009 | Effective |
| 220 (Revised) | Quality Management for an Audit of Financial Statements | Revised 2020 | Effective (periods beginning on or after 15 Dec 2022) |
| 230 | Audit Documentation | Redrafted 2009 | Effective |
| 240 | The Auditor's Responsibilities Relating to Fraud | Redrafted 2009 | Effective |
| 240 (Revised) | The Auditor's Responsibilities Relating to Fraud | Approved 2025 | Not yet effective (periods beginning on or after 15 Dec 2026) |
| 250 (Revised) | Consideration of Laws and Regulations | Revised 2016 | Effective |
| 260 (Revised) | Communication with Those Charged with Governance | Revised 2015 | Effective |
| 265 | Communicating Deficiencies in Internal Control | Redrafted 2009 | Effective |
| 300 | Planning an Audit of Financial Statements | Redrafted 2009 | Effective |
| 315 (Revised 2019) | Identifying and Assessing the Risks of Material Misstatement | Revised 2019 | Effective (periods beginning on or after 15 Dec 2021) |
| 320 | Materiality in Planning and Performing an Audit | Redrafted 2009 | Effective |
| 330 | The Auditor's Responses to Assessed Risks | Redrafted 2009 | Effective |
| 402 | Audit Considerations Relating to an Entity Using a Service Organisation | Redrafted 2009 | Effective |
| 450 | Evaluation of Misstatements Identified During the Audit | Redrafted 2009 | Effective |
| 500 | Audit Evidence | Redrafted 2009 | Effective |
| 501 | Audit Evidence: Specific Considerations for Selected Items | Redrafted 2009 | Effective |
| 505 | External Confirmations | Redrafted 2009 | Effective |
| 510 | Initial Audit Engagements: Opening Balances | Redrafted 2009 | Effective |
| 520 | Analytical Procedures | Redrafted 2009 | Effective |
| 530 | Audit Sampling | Redrafted 2009 | Effective |
| 540 (Revised) | Auditing Accounting Estimates and Related Disclosures | Revised 2018 | Effective (periods beginning on or after 15 Dec 2019) |
| 550 | Related Parties | Redrafted 2009 | Effective |
| 560 | Subsequent Events | Redrafted 2009 | Effective |
| 570 | Going Concern | Revised 2015 | Effective |
| 570 (Revised 2024) | Going Concern | Approved 2024 | Not yet effective (periods beginning on or after 15 Dec 2026) |
| 580 | Written Representations | Redrafted 2009 | Effective |
| 600 (Revised) | Special Considerations: Audits of Group Financial Statements | Revised 2022 | Effective (periods beginning on or after 15 Dec 2023) |
| 610 (Revised 2013) | Using the Work of Internal Auditors | Revised 2013 | Effective |
| 620 | Using the Work of an Auditor's Expert | Redrafted 2009 | Effective |
| 700 (Revised) | Forming an Opinion and Reporting on Financial Statements | Revised 2015 | Effective |
| 701 | Communicating Key Audit Matters in the Independent Auditor's Report | Issued 2015 | Effective |
| 705 (Revised) | Modifications to the Opinion in the Independent Auditor's Report | Revised 2015 | Effective |
| 706 (Revised) | Emphasis of Matter Paragraphs and Other Matter Paragraphs | Revised 2015 | Effective |
| 710 | Comparative Information: Corresponding Figures and Comparative Financial Statements | Redrafted 2009 | Effective |
| 720 (Revised) | The Auditor's Responsibilities Relating to Other Information | Revised 2015 | Effective |
| 800 (Revised) | Special Considerations: Audits of Financial Statements Prepared in Accordance with Special Purpose Frameworks | Revised 2015 | Effective |
| 805 (Revised) | Special Considerations: Audits of Single Financial Statements and Specific Elements, Accounts or Items | Revised 2015 | Effective |
| 810 (Revised) | Engagements to Report on Summary Financial Statements | Revised 2015 | Effective |
ISQM 1 and ISQM 2 (both effective December 2022) sit alongside the ISAs as firm-level and engagement-level quality management standards. The ISA for LCE became effective for periods beginning on or after 15 December 2025.
Worked example: Rossi Alimentari S.p.A.
Client: Italian food production company, FY2025, revenue EUR 67M, IFRS reporter. The engagement partner needs to map applicable ISAs to the FY2025 statutory audit.
Step 1 — Scope in and scope out
All ISAs from 200 through 720 apply (single-entity audit, not a group). ISA 600 (Revised) does not apply because Rossi has no subsidiaries. ISA 701 applies (Rossi is a public-interest entity under Italian law). The 800 series does not apply (IFRS general-purpose framework, full financial statements).
Step 2 — Confirm standard versions
ISA 240 (Revised) and ISA 570 (Revised 2024) are not yet effective for FY2025 (effective date 15 December 2026). The current versions apply. The firm considered early adoption but the Italian professional body has not endorsed it.
Step 3 — Map to engagement phases
Planning (ISA 300, ISA 315 Revised 2019, ISA 320), execution (ISA 330, ISA 500-580, ISA 540 Revised), completion (ISA 450, ISA 560), and reporting (ISA 700 Revised, ISA 701). Rossi's inventory of EUR 9.2M and trade receivables of EUR 14.1M flag ISA 501 and ISA 505 as priorities.
Conclusion: the mapping identifies 32 applicable ISAs, excludes ISA 600 and the 800 series with documented reasons, and confirms that the pre-revision versions of ISA 240 and ISA 570 govern the FY2025 engagement.
Why it matters in practice
The FRC's 2023 Audit Quality Inspection report found firms failing to document which version of a standard applied when transitional periods overlapped. With ISA 220 (Revised), ISA 315 (Revised 2019), ISA 540 (Revised), and ISA 600 (Revised) all becoming effective within a three-year window, some files referenced old-version requirements while applying new-version procedures. ISA 220 (Revised).14 requires the engagement partner to confirm that the firm's policies have been applied, including which edition of each standard the engagement follows.
Smaller firms often treat ISAs as a procedure checklist rather than objectives with required responses. ISA 200.21 frames each ISA around an objective the auditor aims to achieve. Reducing the standard to a tick-box exercise misses conditional requirements triggered only by specific circumstances (ISA 550.18 on related-party transactions outside the normal course of business, for instance).
ISAs vs. national auditing standards
| Dimension | ISAs (IAASB) | National standards (e.g., NV COS, ISAs (UK), IDW PS) |
|---|---|---|
| Issuing body | IAASB, operating under IFAC oversight | National standard-setters (NBA, FRC, IDW, CNCC) |
| Legal force | No direct legal force; adopted by jurisdiction | Legally binding once adopted into national framework |
| Additional requirements | None beyond the ISA text | Often include "ISA plus" requirements (e.g., NV COS adds Dutch-specific provisions on Wwft reporting) |
| Effective dates | Set by the IAASB; jurisdictions may delay or modify | Set by the national body; can lag behind IAASB by 12 to 24 months |
An auditor in the Netherlands applies NV COS (which incorporates the ISAs with local additions), not the ISAs directly. The same pattern applies in Germany (IDW PS series) and the UK (ISAs (UK)). When a firm operates across borders, the engagement partner must confirm which national adoption applies to each statutory audit.
Related terms
Frequently asked questions
Do I have to follow every ISA on every audit?
You must comply with every ISA relevant to the engagement (ISA 200.18). An ISA is relevant whenever the circumstances it addresses exist. If there is no group component, ISA 600 does not apply. Document the scoping decision for any standard you exclude.
When do ISA 240 (Revised) and ISA 570 (Revised 2024) take effect?
Both take effect for periods beginning on or after 15 December 2026. For a December year-end client, the first affected period is FY2027. Early adoption is permitted where the jurisdiction allows it. Check with your national standard-setter first, because local equivalents may follow a different timetable.
What is the ISA for LCE and can I use it instead of the full ISAs?
The ISA for Less Complex Entities is a standalone IAASB standard for audits of entities meeting specified criteria (no public-interest entity status, simple structures, straightforward transactions, uncomplicated financing). Effective for periods beginning on or after 15 December 2025, it provides an alternative framework. Jurisdictions must adopt it separately.