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Advanced Audit and Assurance (International) · Group audits

Component Materiality and Scoping of Components in Group Audits

Updated 11 October 2026 · Fact-checked

Component materiality is a lower threshold set by the group engagement team for each component, so that the total of uncorrected misstatements across the group stays below group materiality. Scoping decides which components get a full audit, specific procedures or analytical review, based on their size and risk to the group financial statements.

Understand Component Materiality and Scoping of Components

A group audit gives one opinion on the consolidated financial statements. The group auditor cannot test every component to group materiality. If each component were audited to group materiality, small errors in many components could add up to a material amount. So the group team sets component materiality at a lower level.

Start with group materiality, set on the consolidated figures using a benchmark such as profit before tax, revenue or total assets. Then set group performance materiality, which is lower than group materiality. Component materiality must be set below group materiality to reduce aggregation risk. It should reflect the component's size, risk and how many components there are. It need not be a simple share of group materiality. The aim is that aggregated uncorrected and undetected misstatements do not exceed group materiality. Component materiality is a judgement, not a simple split or sum of group materiality. The component amounts may add up to more than group materiality only if the group team judges that the risk of aggregated misstatements exceeding group materiality is acceptably low. Different components can have different levels. Under ISA 600 (Revised) the group team may determine component materiality itself, or ask the component auditor to set it and then evaluate it.

Group performance materiality is set lower than group materiality. Component performance materiality is set by the group engagement team, or evaluated by it where the component auditor sets it. It is lower than component materiality, to reduce aggregation risk. The group team communicates these levels to component auditors.

Next comes scoping. The group team decides what work each component needs. Under ISA 600 (Revised) the approach is risk-based. The group team uses its risk assessment to identify risks of material misstatement of the group statements, then designs responses to those risks. In doing so you consider each component's financial significance and its likelihood of containing such risks.

Significant component is the term from the previous ISA 600. It is not the framework of ISA 600 (Revised), but it is still widely used in exam answers as a handy label, so you can use it. Two typical groups appear. Significant components are those that are individually financially significant to the group, or that are likely to include significant risks of material misstatement because of their specific nature or circumstances. Non-significant components are the rest. Always link the label to the risk-based reasoning.

For components that are significant, the usual response is an audit of the component's financial information using component materiality. Where a component is significant because of a specific risk, audit of specific account balances, classes of transactions or disclosures related to that risk may be enough. For non-significant components, the group team may perform analytical procedures at group level, or limited procedures, and then check that enough evidence has been covered overall. If coverage seems too low, extend work to more components, including some unpredictable choices.

In the exam, always link your scoping to the scenario. Name the component, state its size or risk, say what scope you recommend, and say why. Also comment on who does the work: the group team or a component auditor, and how you will direct and review them.

Key rules to remember

Component materiality rule
Component materiality < Group materiality
Set lower so that the aggregate of uncorrected and undetected misstatements across components stays below group materiality. Not a fixed percentage.
Indicative size test for significance
Component benchmark ÷ Group benchmark × 100
A rule-of-thumb only. A large share suggests the component is financially significant. ISA 600 (Revised) gives no fixed percentage, so state your threshold as a judgement.
Group performance materiality
Group performance materiality < Group materiality
Set to reduce the risk that aggregated uncorrected and undetected misstatements exceed group materiality.
Component performance materiality
Component performance materiality < Component materiality
Set by the group engagement team, or evaluated by it where the component auditor sets it. It is lower than component materiality to reduce aggregation risk.
Scoping decision
Significant by size or by risk → audit (full or specific balances); Not significant → analytical procedures or limited work, plus a coverage check
Risk-based. A small component can still be significant if it carries a significant risk. 'Significant component' is the previous ISA 600 term, still widely used in exam answers.

How to solve Component Materiality and Scoping of Components questions

Use this order for any question on component materiality or scoping. Keep every point tied to the scenario figures.

  1. 1Read the requirement. Decide if you must set materiality, choose scope, explain a term, or comment on coverage.
  2. 2Identify the group benchmark and group materiality. If not given, choose a benchmark that suits the group (for example profit before tax for a profit-making group) and state it.
  3. 3Set component materiality below group materiality. Explain that it is lower to allow for aggregation, and that larger or riskier components may get different levels.
  4. 4Calculate each component's share of the group benchmark (revenue, profit or assets). Note any component with unusual risk: new systems, fraud, foreign currency, regulatory problems, complex estimates, going concern doubt.
  5. 5Classify each component as significant by size, significant by risk, or non-significant. Give the reason in one sentence.
  6. 6Assign scope: audit with component materiality; audit of specific balances tied to the risk; or analytical procedures and limited work at group level.
  7. 7Check overall coverage of group revenue, profit and assets. If coverage looks too low, extend work to further components.
  8. 8Say who performs the work and how the group team will direct, supervise and review it. Add professional scepticism and communication points.

Quickest way: Size, risk, scope in three passes

When to use it: Use when the scenario lists several components in a table and time is short.

  1. Pass 1: work out each component's percentage of group revenue, profit and assets. Mark any that look large.
  2. Pass 2: circle any component with a specific risk (fraud, new system, overseas regulation, unusual transactions, going concern).
  3. Pass 3: write one line per component: name, reason, scope, who does it.
  4. Add one line that component materiality is set below group materiality, and one line on checking coverage of the group.

Common mistakes in Component Materiality and Scoping of Components

  • Setting component materiality equal to group materiality.

    Students assume each component is just a smaller audit and forget that errors aggregate.

    Fix: State that component materiality must be lower than group materiality so that the total of uncorrected misstatements stays below it.

  • Dividing group materiality by the number of components and calling it component materiality.

    It looks neat and numerical.

    Fix: Say it is a matter of judgement based on each component's size and risk. The sum of component materialities may exceed group materiality only if the group team judges that the risk of aggregated misstatements exceeding group materiality is acceptably low.

  • Scoping only on size and ignoring risk.

    Size is easy to calculate from a table.

    Fix: Check each component for significant risks. A small component with a fraud or complex estimate risk may need audit procedures on the affected balances.

  • Assuming non-significant components need no work at all.

    Students read non-significant as unimportant.

    Fix: Recommend analytical procedures at group level and test overall coverage. Extend work if coverage is not enough.

  • Giving a scope without saying who does the work.

    Students focus on the technical label and forget direction and review.

    Fix: Add a line on whether the group team or a component auditor performs the work, and how you will communicate requirements and review their work.

  • Stating fixed percentages for significance as if the standard requires them.

    Textbooks and firms often quote rules of thumb.

    Fix: Call any percentage a firm policy or a judgement. ISA 600 (Revised) does not set a required percentage.

Worked examples

Example 1

Alpha Group has consolidated profit before tax of $20 million. The group team sets group materiality at 5% of profit before tax. Component Beta contributes $9 million of the group's profit before tax. Explain how the group team should approach component materiality for Beta and calculate group materiality.

Show the solution
  1. Group materiality = 5% × $20,000,000 = $1,000,000.
  2. Component materiality for Beta must be set below $1,000,000. The exact figure is a judgement.
  3. Beta is 9 ÷ 20 = 45% of group profit before tax, so it is a large component and likely significant by size.
  4. Do not assume a large component should have a level close to group materiality. Any figure is judgemental and must reflect the risk that misstatements aggregate across components. A figure such as $650,000 is illustrative only and is not required. The group team must give its reasons.
  5. The reason for the lower level is aggregation: misstatements across all components must stay below $1,000,000 in total, unless the group team judges the risk of that happening is acceptably low.

Answer: Group materiality is $1,000,000. Beta's component materiality must be lower. Any figure is a judgement that reflects aggregation risk, and $650,000 is illustrative only. Beta is 45% of group profit before tax, so it is a significant component and needs an audit using component materiality.

Example 2

Gamma Group has three components. Revenue: Delta $60 million, Epsilon $30 million, Zeta $10 million (group total $100 million). Zeta is a small overseas subsidiary that recently introduced a new accounting system and has significant related party sales. Recommend the scope for each component.

Show the solution
  1. Delta is 60 ÷ 100 = 60% of group revenue. It is financially significant, so an audit of its financial information using component materiality is needed.
  2. Epsilon is 30 ÷ 100 = 30% of group revenue. It is also likely to be financially significant, so a full audit is appropriate.
  3. Zeta is 10 ÷ 100 = 10% of group revenue, so it is not significant by size.
  4. Zeta has a new system and significant related party sales, so it may contain a significant risk of material misstatement for the group.
  5. Recommend specific procedures on Zeta's revenue, related party transactions and system migration balances, rather than analytical review alone.
  6. Check coverage: Delta and Epsilon give 90% of revenue, plus Zeta's targeted work. Coverage looks sufficient but should also be checked against profit and assets.
  7. State that the group team will direct and review the component auditors' work, with particular attention to Zeta because of its overseas location and risks.

Answer: Audit Delta and Epsilon in full using component materiality. For Zeta, perform specific procedures on revenue, related party transactions and the new system, because it is significant by risk although not by size. Check coverage against profit and assets and direct and review component auditors' work.

Exam tips

  • Show a calculation when figures are given, then add the judgement. Markers reward both the number and the reasoning.
  • Always say component materiality is lower than group materiality and explain aggregation in one sentence.
  • Use the words significant by size and significant by risk. They map neatly to marks.
  • Tie each scope to a specific fact in the scenario. Generic textbook lists score poorly.
  • Add a professional skills point: for example, advise the engagement partner clearly on coverage gaps and communicate requirements to component auditors.

Practice questions from Group audits

Component Materiality and Scoping of Components in other exams

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

Component Materiality and Scoping of Components: frequently asked questions

How do you set component materiality under ISA 600?

The group team sets it using judgement, below group materiality. It reflects the component's size and risk and the need to keep aggregated misstatements below group materiality. There is no fixed formula, so explain your reasoning.

What is the difference between a significant and a non-significant component?

A significant component is financially significant to the group, or likely to include significant risks of material misstatement of the group statements. A non-significant component is neither. Significant ones usually get an audit or specific procedures. Others usually get analytical procedures and limited work.

Does a small component ever need an audit?

Sometimes it needs audit work on specific balances. If it carries a significant risk, such as fraud or a complex estimate, you should audit the affected balances or transactions even though the component is small.

What if coverage of the group is too low after scoping?

Extend the work. Select further components for audit or specific procedures, including some chosen unpredictably, until you can obtain sufficient appropriate evidence on the group financial statements.