Cost and Management Audit · Internal Control and Internal Audit

Internal Audit versus Management and Cost Audit Linkages

Updated 11 October 2026 · Fact-checked

Internal audit is an in-house review of controls, risks and operations for management. Cost audit verifies cost records under section 148 and reports to the Board. Management audit appraises managerial effectiveness. Under SA 610 (Revised), the external auditor decides whether and how far to use internal audit work, but keeps sole responsibility for the opinion.

Understand Internal Audit versus Management and Cost Audit Linkages

Start with who the audit is for and what it checks. Internal audit is an ongoing review of the company's functions, activities, controls and risks. It is done for management and the Board. Under section 138 of the Companies Act, 2013, prescribed classes of companies must appoint an internal auditor. This person is a chartered accountant, a cost accountant, or another professional the Board decides.

Cost audit is different. Under section 148, the Central Government may direct that cost records of prescribed companies be audited. The auditor is a cost accountant appointed by the Board. The cost auditor must follow the cost auditing standards and submits the report to the Board. It is a statutory audit, and it is in addition to the audit under section 143.

Management audit looks at the quality of management itself: policies, planning, organisation, decision-making and use of resources. Operational audit examines the efficiency, economy and effectiveness of specific operations or functions. Internal audit often covers operational audit, and the two overlap heavily. The difference is that internal audit is the wider function. Operational audit is one type of work it can perform.

The linkages are practical. Internal audit findings on stores, purchasing or production controls help the cost auditor judge the reliability of cost records. Internal audit work on efficiency feeds management audit. The audit committee under section 177 ties these together. Its terms of reference include evaluating internal financial controls and risk management systems, and it may discuss related issues with the internal and statutory auditors. It can also call for the auditors' comments on internal control systems and the scope of audit.

SA 610 (Revised) deals with the external auditor using the work of internal auditors. SA 315 explains how the knowledge and experience of the internal audit function can inform the external auditor's understanding of the entity and the assessment of risks of material misstatement. Reliance is a judgement. The external auditor evaluates the function's objectivity, competence and quality of work. Using the work does not reduce the external auditor's responsibility for the opinion.

Key rules to remember

Section 138(1): internal auditor: Prescribed class of companies → appoint internal auditor (CA, cost accountant or other professional decided by the Board); The class of companies is set by rules. Do not state thresholds unless the question gives them.
Section 148(3): cost auditor: Cost accountant appointed by the Board; must comply with cost auditing standards; A person appointed as statutory auditor under section 139 cannot be appointed for the cost audit of the same company.
Section 148(4) and (5): Cost audit is in addition to the section 143 audit; report goes to the Board; The company must give the cost auditor all assistance and facilities.
Section 177(4)(vii): Audit committee terms of reference include evaluation of internal financial controls and risk management systems; This is the link between the audit committee and internal audit.
Section 177(2): Audit committee: minimum three directors, independent directors in majority; The Chairperson and a majority of members must be able to read and understand financial statements.
Reliance principle (SA 610): Reliance = evaluate objectivity + competence + systematic and disciplined approach; responsibility for opinion stays with external auditor; Use this as a memory frame. The standard's detailed paragraphs are not reproduced here.

How to solve Internal Audit versus Management and Cost Audit Linkages questions

Use this method for any question that compares the audits or asks about reliance on internal audit.

1Identify the audits named in the question and note who appoints each one and to whom it reports.
2Compare them on purpose, coverage, statutory backing and independence. Keep each point to one line.
3State the statutory basis where you are sure: section 138 for internal audit, section 148 for cost audit, section 177 for the audit committee.
4Show the linkage: which findings of one audit help the other, and how the audit committee or Board receives them.
5If reliance is asked, apply the SA 610 logic: assess objectivity and competence, judge quality of work, then decide the extent of use.
6Close with the principle that the external auditor alone is responsible for the opinion, and give a clear conclusion for the case.

Quickest way: Four-column comparison

When to use it: Use when the question says differentiate, distinguish or compare internal audit, cost audit, management audit or operational audit.

Draw four points: purpose, who appoints and reports, legal status, focus.
Write internal audit: controls and risks, for management and Board, required for prescribed classes under section 138.
Write cost audit: cost records, cost accountant appointed by Board, statutory under section 148.
Write management audit and operational audit: managerial effectiveness and efficiency of operations, not statutory in itself.
Add one line on the SA 610 reliance link and finish.

Common mistakes in Internal Audit versus Management and Cost Audit Linkages

Saying the cost auditor reports to the Central Government directly.
Students mix up the report's submission by the company with who receives it from the auditor.
Fix: Write that the cost auditor submits the report to the Board. The company then furnishes it to the Central Government within thirty days of receiving it, with explanations for every reservation or qualification.
Treating internal audit as only a check on accounting records.
Students carry over the idea of financial audit.
Fix: Internal audit covers functions, activities, controls and risks, not only accounts.
Writing that the external auditor can transfer responsibility by relying on internal audit.
The word reliance suggests handing over the work.
Fix: State that using internal audit work does not reduce the external auditor's responsibility for the opinion.
Calling operational audit and management audit the same thing.
Both examine efficiency and effectiveness.
Fix: Operational audit focuses on specific operations or functions. Management audit appraises the quality of management and its decisions. Show the overlap but keep the focus distinct.
Saying the statutory auditor can also be appointed as cost auditor of the same company.
Students assume both audits are one engagement.
Fix: Quote the proviso to section 148(3): a person appointed as auditor under section 139 cannot be appointed for the audit of cost records. The cost audit is also separate from the section 143 audit.
Stating that every company must have an internal auditor.
Section 138 is remembered without its condition.
Fix: Say that prescribed classes of companies must appoint one.

Worked examples

Example 1

Distinguish between internal audit and cost audit under the Companies Act, 2013. (6 marks)

Show the solution

Purpose: internal audit reviews functions, activities, controls and risks for management. Cost audit verifies cost records and cost information.
Basis: internal audit is required under section 138 for prescribed classes of companies. Cost audit is directed under section 148 for prescribed companies by the Central Government.
Appointer: the Board appoints the internal auditor, who is a CA, a cost accountant or another professional the Board decides. The Board appoints a cost accountant as cost auditor, with remuneration determined by the members.
Standards: the cost auditor must comply with the cost auditing standards issued by the Institute. Internal audit scope is set by the Board or audit committee within the rules.
Relationship to the statutory audit: cost audit is in addition to the section 143 audit, and the section 139 auditor cannot be the cost auditor. Internal audit is not a replacement for the statutory audit.
Report: both reports go to the Board. The cost audit report is also furnished by the company to the Central Government within thirty days of receipt.

Answer: Internal audit is a management-oriented review of controls and operations required for prescribed classes under section 138. Cost audit is a statutory audit of cost records under section 148, performed by a cost accountant under cost auditing standards, and it is separate from the section 143 audit.

Example 2

Pragati Steels Ltd, a listed company, has an internal audit team that reports to the audit committee. The statutory auditor wants to use its work on stores and purchases controls. Advise how the auditor should approach this, and how the work links to the cost auditor. (8 marks)

Show the solution

Start with SA 315: the knowledge and experience of the internal audit function can inform the auditor's understanding of the entity and the assessment of risks of material misstatement.
Evaluate the function under SA 610 logic: its objectivity (reports to the audit committee, which supports independence), its competence, and whether it works in a systematic and disciplined way.
If these are satisfactory, plan the extent of use. Areas with higher judgement or risk need more direct audit work by the auditor.
Review and test a sample of the internal audit work used, to confirm it is adequate for the purpose.
Record that responsibility for the opinion stays with the statutory auditor. Reliance does not reduce it.
Link to cost audit: controls over stores and purchases support the reliability of material costs. The cost auditor, a separate appointee under section 148, may consider the internal audit findings when planning the cost audit, but forms an independent conclusion.
Link to governance: the audit committee, under section 177, evaluates internal financial controls and can discuss related issues with the internal and statutory auditors.

Answer: The statutory auditor should assess the internal audit function's objectivity and competence, judge its work quality, decide the extent of use, and test the work used. The opinion remains solely the auditor's responsibility. The same findings help the cost auditor in planning, but each auditor reaches an independent conclusion.

Exam tips

For differentiate questions, write in a compact comparison with four or five points, each one line, and add the legal section where you are sure.
Always add one sentence that the external auditor's responsibility for the opinion is not reduced by reliance on internal audit.
In case scenarios, name the company's facts, such as the audit committee reporting line, and use them as evidence of objectivity.
For MCQs, watch the appointer and the reporting line: the cost auditor is appointed by the Board and reports to the Board.
Do not quote thresholds or rule numbers for section 138 or 148 unless the question supplies them.

Practice questions from Internal Control and Internal Audit

Internal Audit versus Management and Cost Audit Linkages in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Internal Audit versus Management and Cost Audit Linkages: frequently asked questions

Can the statutory auditor rely fully on the internal auditor's work?

No. The external auditor evaluates the internal audit function and decides the extent of use. Responsibility for the audit opinion stays with the external auditor, so reliance can never be total delegation.

What is the difference between internal audit and operational audit?

Internal audit is the wider function that reviews controls, risks and activities of the company. Operational audit is a type of review focused on the efficiency, economy and effectiveness of operations, and internal auditors often perform it.

Is cost audit a part of internal audit?

No. Cost audit is a statutory audit under section 148 of the Companies Act, 2013, done by a cost accountant appointed by the Board. It is separate from internal audit and from the section 143 audit.

Who must appoint an internal auditor under section 138?

Such class or classes of companies as are prescribed. The internal auditor may be a chartered accountant, a cost accountant, or another professional decided by the Board.