IAASB ISA: International Standards on Auditing Guide

The International Standards on Auditing (ISAs) are the globally recognized standards for performing financial statement audits. Issued by the IAASB under the oversight of the International Federation of Accountants (IFAC), ISAs are adopted or used as the basis for national auditing standards in over 130 jurisdictions. They establish the auditor's responsibilities for planning, performing, and reporting on financial statement audits with the objective of obtaining reasonable assurance about whether the financial statements are free from material misstatement.

What the ISAs Cover

The ISAs comprise over 35 standards organized by topic area. Key standards include ISA 200 (overall objectives), ISA 315 (risk identification and assessment), ISA 330 (responses to assessed risks), ISA 500 (audit evidence), ISA 540 (accounting estimates), ISA 570 (going concern), ISA 600 (group audits), and ISA 700-706 (forming and reporting opinions).

The ISAs follow a risk-based approach: auditors identify and assess risks of material misstatement, design and perform audit procedures responsive to those risks, and obtain sufficient appropriate evidence to support their opinion. The 2024 updates include the revised ISA 600 for group audits and ongoing work on fraud, going concern, and the audit of less complex entities (ISA for LCE).

Who Needs to Understand ISAs

Audit firms worldwide that perform statutory or voluntary financial statement audits must comply with ISAs (or their national equivalents). Companies undergoing financial statement audits benefit from understanding ISA requirements to prepare effectively and engage productively with their auditors. Audit committees and boards should understand ISA concepts to fulfill their oversight responsibilities.

The Audit Process Under ISAs

Engagement acceptance and planning (ISA 300), understanding the entity and its environment (ISA 315), materiality determination (ISA 320), risk assessment and response (ISA 315/330), evidence gathering through substantive procedures and tests of controls (ISA 500/530), evaluation of misstatements (ISA 450), going concern assessment (ISA 570), and forming and issuing the opinion (ISA 700).

Cost Considerations

Financial statement audit fees under ISAs vary enormously by entity size and complexity. Small companies may pay $10,000 to $50,000 annually. Mid-sized companies typically pay $50,000 to $200,000. Large listed companies pay $500,000 to several million. Audit fees are determined by the auditor's risk assessment, the entity's complexity, and the scope of required procedures. Understanding ISA requirements helps organizations reduce audit friction and potentially lower fees through better preparation.