The Financial Reporting Council has published final revisions to UK auditing and assurance standards governing the use of external experts.
Scope of the Revised Auditing and Assurance Standards
The update affects ISA (UK) 620 (Revised September 2026), which addresses using the work of an auditor’s expert, and ISAE (UK) 3000 (Revised September 2026), covering assurance engagements other than audits or reviews of historical financial information.
The revisions maintain alignment with international standards established by the International Auditing and Assurance Standards Board and ensure interoperability with the International Code of Ethics for Professional Accountants issued by the International Ethics Standards Board for Accountants.
Key Requirements and Effective Date
The updated standards align definitions and responsibilities for evaluating an external expert’s competence, capabilities, and objectivity. They also clarify practitioner duties and reinforce the requirements for thorough evaluation and documentation.
According to the FRC, maintaining common standards across jurisdictions helps lower reporting and audit costs while supporting consistent quality across audits.
The revised standards take effect for audits of financial statements for periods commencing on or after 15 December 2026, as well as for assurance reports dated on or after 15 December 2026.
| Standard Reference | Title and Subject Area |
|---|---|
| ISA (UK) 620 (Revised September 2026) | Using the Work of an Auditor’s Expert |
| ISAE (UK) 3000 (Revised September 2026) | Assurance Engagements Other Than Audits or Review of Historical Financial Information |
Frequently Asked Questions
Which FRC standards have been revised?
The FRC revised ISA (UK) 620 (Revised September 2026) on using an auditor’s expert and ISAE (UK) 3000 (Revised September 2026) for non-audit assurance engagements.
When do the revised FRC standards become effective?
The revised standards apply to audits of financial statements for periods commencing, and assurance reports dated, on or after 15 December 2026.
