ISCA Issues EP 100 (revised on 20 October 2026) to Adopt the IESBA’s External Experts and Sustainability-related Standards

EP 100 Code of Professional Conduct and Ethics (EP 100) establishes ethical requirements for members of the Institute of Singapore Chartered Accountants (ISCA) and is modelled after the International Code of Ethics for Professional Accountants (including International Independence Standards) issued by the International Ethics Standards Board for Accountants (IESBA).

ISCA has issued EP 100 (revised on 20 October 2026) 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 Changes

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. Part 5 is profession-agnostic and framework-neutral, supporting consistent application by SAPs regardless of their professional background or the reporting or assurance framework used.

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. It also 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)
  
  

Scope of the Independence Standards in Part 5

The Independence Standards in Part 5 apply to SAEs with the same level of public interest as audits of financial statements. The criteria determined for such engagements are set out in paragraph 5400.3b, where the sustainability information on which the SAP expresses an opinion:

The table below summarises the relevant ethics and independence standards applicable for SAEs: 

Voluntary Use and Application of Part 5

The Accounting and Corporate Regulatory Authority (ACRA) has established an Interim Sustainability Standards Committee (Interim SSC) to set the assurance, ethics and independence standards for SAPs in Singapore. ISCA has been working with ACRA to review the provisions of the IESSA FP, including new Section 5390 introduced by the Experts FP, and to consider feedback from relevant stakeholders, including non-accountant SAPs. ISCA has recommended, and the Interim SSC has approved, the adoption of the IESSA into Parts 4B and 5 of EP 100 (revised on 20 October 2026).

Part 5 of EP 100 (revised on 20 October 2026) has been issued by ISCA for voluntary use, subject to the effective dates set out below. Following enactment of the relevant legislation and the formal constitution of the Sustainability Standards Committee, Part 5 of EP 100 is expected to be adopted for application by SAPs providing mandatory climate assurance under Singapore’s climate reporting and assurance roadmap. Mandatory climate assurance will be introduced in phases as follows:

• From FY2029, all listed issuers will be required to obtain limited assurance on their Scope 1 and Scope 2 greenhouse gas (GHG) emissions.
• From FY2032, all large non-listed companies will be required to obtain limited assurance on their Scope 1 and Scope 2 GHG emissions.
  

Effective Date

Except for the provisions in Sections 5405 and 5406 applicable to assurance work performed at VCCs, EP 100 (revised on 20 October 2026) is effective for periods beginning (or as at a specific date) on or after 15 December 2026.

The provisions in Sections 5405 and 5406 under Part 5 of EP 100, applicable when assurance work is performed at a VCC, are effective for SAEs on sustainability information for periods beginning (or as at a specific date) on or after 1 July 2028.

Please click here for EP 100 (revised on 20 October 2026).