CORAA

SIA 350 — Review and Supervision of Audit Assignments

ICAI Internal Audit Standards Board · October 2022 compendium · 300 series
Reviewed 1 October 2026

SIA 350 covers review and supervision during an assignment: confirming or updating the plan, evaluating the procedures, evidence, documentation and conclusions produced by staff, helping to shape observations and draft the report, and confirming that the Standards on Internal Audit were followed throughout.

This page covers SIA 350 as it stands in ICAI’s October 2022 compendium. ICAI’s February 2026 compendium, applicable from 1 April 2026, renumbers the standards, so check the current number and text in that compendium before citing it in a report.

What the internal auditor has to do

  • As Chief Internal Auditor or Engagement Partner, take overall responsibility for review and supervision.
  • Have every working paper reviewed at least one level up.
  • Plan how often and how deeply work will be reviewed, and document that at the planning stage.
  • Keep a written review process.
  • Sign and date the review on the working papers and record the follow-up points raised.

Key requirements of SIA 350

Paragraph numbers refer to SIA 350 as it appears in ICAI’s Compendium of Standards on Internal Audit (as on 1 October 2022). The points below are close paraphrases, not quotations.

  • The Chief Internal Auditor or Engagement Partner has overall responsibility for review and supervision, and every working paper is reviewed at least one level up.(para 3.1, 4.1)
  • The periodicity and extent of review are planned and documented at the planning stage.(para 3.2)
  • The review confirms that the reviewer could reach the same conclusions, and this is recorded with evidence.(para 3.3, 4.2)
  • A written review process is maintained.(para 3.4)
  • Review is documented by the signature and date of review on the working papers, together with the follow-up points raised.(para 4.4(b))
  • Review may be delegated to experienced staff, but responsibility stays with the Chief Internal Auditor.(para 4.1)
  • The review checklist in Annexure 1 includes the rationale for excluding draft observations from the report.

How SIA 350 shows up in the internal audit file

  • Reviewer signature and date on each working paper.
  • Review notes and how each point was cleared.
  • The planned frequency and extent of review, recorded at planning.
  • For any draft observation left out of the report, the reason it was dropped.

Common mistakes in practice

  • A single review at the end of the assignment, after the draft report has gone out.
  • Review points raised and cleared verbally, leaving no trace.
  • Draft observations dropped from the report with no reason recorded.
  • Treating delegation of review as delegation of responsibility.

The file checklist and the mistakes above are practice points drawn from the requirements of the standard. They are not text from the standard.

Related standards

SIA 330 · Internal Audit DocumentationSIA 320 · Internal Audit EvidenceSIA 370 · Reporting ResultsSIA 7 · Quality Assurance in Internal Audit

How this relates to global frameworks

The IIA's Global Internal Audit Standards (effective 9 January 2025) are a separate set from a different body, and there is no paragraph-for-paragraph match. The closest IIA principles are Conduct Engagement Work and Enhance Quality.

Status and source

This standard is described here as it stands in the October 2022 compendium, which is the earlier set. ICAI's Internal Audit Standards Board lists its Compendium of Standards on Internal Audit (as on February 2026) as applicable from 1 April 2026 (source: the Board's compendium page, checked on 1 October 2026). That compendium renumbers the standards, so check the current number and text there before citing this standard in a report. ICAI's compendium page does not say whether the standards are mandatory or recommendatory, so we do not describe any standard as mandatory. The effective-date clause in each 2019 standard said it applied to internal audits beginning on or after a date to be notified by the Council of ICAI.

These pages summarise each standard as it stands in ICAI's Compendium of Standards on Internal Audit (as on 1 October 2022), working from an extract of that document. They are summaries and close paraphrases, not the text of the standards. ICAI's Internal Audit Standards Board lists its Compendium of Standards on Internal Audit (as on February 2026) as applicable from 1 April 2026 (source: the Board's compendium page, checked on 1 October 2026). For that current set we have only the titles, taken from the Board's 2025-26 annual report; its text is available from ICAI through a registration form on the compendium page and is not summarised here. ICAI's compendium page does not say whether the standards are mandatory or recommendatory, so we do not describe any standard as mandatory. Before you cite a number, a paragraph or a status in a report, check the February 2026 compendium. internalaudit.icai.org

Free working files for SIA 350

Take the working versions with you

Editable formats and tools from CORAA’s internal audit library that put SIA 350 into practice. Free to use.

Internal Audit Quality Assurance & Improvement Program →Quality review checklist →Fieldwork testing tracker →

SIA 350 — frequently asked

What is SIA 350?

SIA 350, Review and Supervision of Audit Assignments, is a Standard on Internal Audit issued by the Internal Audit Standards Board of ICAI. SIA 350 covers review and supervision during an assignment: confirming or updating the plan, evaluating the procedures, evidence, documentation and conclusions produced by staff, helping to shape observations and draft the report, and confirming that the Standards on Internal Audit were followed throughout.

Is SIA 350 mandatory?

ICAI's compendium page does not say whether the Standards on Internal Audit are mandatory or recommendatory, so we do not describe SIA 350 as mandatory. ICAI's Internal Audit Standards Board lists its Compendium of Standards on Internal Audit (as on February 2026) as applicable from 1 April 2026 (source: the Board's compendium page, checked on 1 October 2026). SIA 350 as described on this page is from the earlier October 2022 compendium. The February 2026 compendium renumbers the standards, so check the current number and text there before citing it in a report.

What should the internal audit file show for SIA 350?

Reviewer signature and date on each working paper. Review notes and how each point was cleared. The planned frequency and extent of review, recorded at planning. For any draft observation left out of the report, the reason it was dropped.

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SIA 330 — Internal Audit Documentation
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