ISCA Issues EP 100 Exposure Draft to Adopt the IESBA’s External Experts and Sustainability-related Standards

ISCA issues the Exposure Draft – Proposed Changes to EP 100 Code of Professional Conduct and Ethics (EP 100 ED) for public consultation to adopt two IESBA final pronouncements (FPs):

• Revisions to the Code Addressing Using the Work of an External Expert (Experts FP); and

• International Ethics Standards for Sustainability Assurance (including International Independence Standards) and Other Revisions to the Code Relating to Sustainability Assurance and Reporting (IESSA FP).

Key Elements of the Proposed Changes to EP 100

Under the Experts FP, new sections 290, 390 and 5390 establish an ethical framework to guide professional accountants and sustainability assurance practitioners (SAPs) in evaluating whether an external expert has the necessary competence, capabilities and objectivity in order to use that expert’s work for the intended purposes.

The IESSA FP introduces a new Part 5 designed for use by all SAPs including audit firms, conformity assessment bodies and other practitioners. Accordingly, Part 5 has been developed in a profession-agnostic and framework-neutral manner, allowing the standard to be applied consistently by SAPs regardless of their background, and to support any reporting or assurance framework. Part 5 establishes the same high standards of ethical behaviour and independence for sustainability assurance engagements (SAEs) as the provisions that currently apply to audits of financial statements.  

In addition, Part 5 recognises the specific characteristics of SAEs and reflects ethics and independence considerations related to:

• The use of the work of an external expert in the context of SAEs. (new Section 5390)

• A group sustainability assurance firm or a component practitioner that performs assurance work at a value chain component (VCC). (subsection B of new Section 5405)

• The use of the assurance work of another practitioner, who is not a component practitioner, for purposes of an SAE. (new Section 5406)

Effective Date

Except for Sections 5405 and 5406, the proposed changes to EP 100 will be effective for SAEs on sustainability information for periods beginning on or after 15 December 2026, or as at a specific date on or after 15 December 2026.

The provisions in Sections 5405 and 5406 of EP 100 (applicable when assurance work is performed at a VCC) will be effective for SAEs on sustainability information for periods beginning on or after 1 July 2028, or as at a specific date on or after 1 July 2028.

Please send your comments on the EP 100 ED to adopt the Experts and IESSA FPs to professionalstandards@isca.org.sg by 8 December 2025.