Audit and Assurance · The concept of audit and other assurance engagements

Introduction to Assurance Engagements for ACCA AA

Updated 11 October 2026 · Fact-checked

An **assurance engagement** is one where a practitioner gives a conclusion that increases the confidence of intended users about a subject matter, measured against criteria. It has five elements: a three-party relationship, appropriate subject matter, suitable criteria, sufficient appropriate evidence and an assurance report (conclusion). Services missing these elements, such as tax advice, are non-assurance.

Understand Introduction to Assurance Engagements

Assurance means giving users more confidence about information or a situation. A bank wants to trust a company's financial statements. It cannot check every transaction, so it relies on an independent professional who has done work and reports a conclusion.

The audit of financial statements is the best-known assurance engagement. But it is not the only one. A practitioner can also give assurance on sustainability reports, internal controls, cyber security or a prospective forecast. The framework is the same each time.

Every assurance engagement has five elements. First, a three-party relationship: the practitioner, the responsible party (who is accountable for the subject matter) and the intended users. Second, an appropriate subject matter, which is the information or activity being examined. Third, suitable criteria, the benchmarks used to evaluate the subject matter, such as IFRS Accounting Standards for financial statements. Fourth, sufficient appropriate evidence, obtained through the practitioner's procedures. Fifth, an assurance report containing the written conclusion.

The practitioner must be independent of the responsible party. Without independence, users cannot rely on the conclusion. The level of assurance can be reasonable or limited. Reasonable assurance gives a positive form of conclusion, as in an audit. Limited assurance gives a negative form of conclusion, as in a review (for example, "nothing has come to our attention").

Non-assurance services do not give a conclusion on a subject matter for third-party users. Examples are tax advice, preparing financial statements and consultancy. Related services, such as agreed-upon procedures and compilation, are also not assurance engagements. In agreed-upon procedures the practitioner reports findings but gives no conclusion. In compilation the practitioner helps prepare information and gives no assurance on it. The client or the parties draw their own conclusions from the work.

Key rules to remember

Five elements of an assurance engagement: Three-party relationship + Subject matter + Criteria + Sufficient appropriate evidence + Assurance report (conclusion); If any element is missing, the engagement is not an assurance engagement.
Three parties: Practitioner + Responsible party + Intended users; The responsible party and the intended users can be different people, and the responsible party can also be a user. The practitioner is always separate.
Levels of assurance: Reasonable assurance = positive form of conclusion (audit); Limited assurance = negative form of conclusion (review); Reasonable is high but not absolute. Absolute assurance is never given.
Suitable criteria: Relevance, completeness, reliability, neutrality, understandability; Use these to test whether criteria are suitable. Without suitable criteria, the subject matter cannot be evaluated consistently.

How to solve Introduction to Assurance Engagements questions

Use this method for any question asking whether an engagement is assurance, or asking you to explain the elements.

1Read the scenario and identify who is doing the work, who is responsible for the information, and who will use the result.
2Check for a three-party relationship. If the practitioner is working only for the client's own use with no outside users, be cautious.
3Identify the subject matter and decide whether it is appropriate, meaning it can be identified and evaluated.
4Identify the criteria. Ask what the subject matter is being measured against and whether those criteria are suitable.
5Look for evidence-gathering procedures and a conclusion. Does the practitioner give an opinion or conclusion, or only report facts or findings?
6Decide: assurance if all five elements are present, non-assurance if one is missing, usually the conclusion.
7State the level of assurance (reasonable or limited) if the question asks, and link every point to the scenario facts.

Quickest way: The conclusion test

When to use it: Use this in Section A, which has three 10-mark OT cases, each with five 2-mark questions. Each 2-mark question gets roughly 3.6 minutes (1.8 minutes per mark). Apply it in Section B constructed response questions where relevant.

Ask: does the practitioner give a conclusion that increases users' confidence?
If no conclusion, such as only findings, advice or preparation of information, choose non-assurance (or a related service).
If yes, quickly check for three parties and criteria.
For element-identification questions, match the item to its label: who (parties), what (subject matter), against what (criteria), how (evidence), result (assurance report and conclusion).
Eliminate options that claim absolute assurance.

Common mistakes in Introduction to Assurance Engagements

Treating every service a firm provides as assurance.
Students link anything done by an audit firm with audit.
Fix: Ask whether a conclusion is given to users. Tax advice, bookkeeping and consultancy are non-assurance services. Agreed-upon procedures and compilation are related services. None of these is assurance.
Saying the practitioner is the responsible party.
The practitioner is doing the work, so students assume they are responsible for the information.
Fix: The responsible party is accountable for the subject matter, for example directors for the financial statements. The practitioner gives a conclusion on it.
Confusing subject matter with criteria.
Both relate to the financial statements in an audit.
Fix: Subject matter is what is examined (the financial statements). Criteria is the benchmark (IFRS Accounting Standards).
Claiming reasonable assurance means a guarantee.
The word reasonable is read as certain.
Fix: Reasonable assurance is high but not absolute, because of inherent limitations such as sampling and judgement.
Saying agreed-upon procedures give limited assurance.
Students see that some work is done and assume some assurance results.
Fix: In agreed-upon procedures the practitioner reports factual findings and gives no conclusion, so no assurance is provided. It is a related service.
Listing the elements without applying them to the scenario.
Students memorise the list but do not link it to the facts.
Fix: For each element, name the specific party, subject matter or criteria from the scenario.

Worked examples

Example 1

A firm of accountants is engaged by the board of Orbit Co to report to its bank on whether Orbit Co's covenant calculations comply with the loan agreement terms. The engagement is designed to give reasonable assurance. The firm performs tests to obtain sufficient appropriate evidence and issues a written positive opinion to the bank. Identify the five elements of this assurance engagement and state the level of assurance.

Show the solution

Three-party relationship: the accountants are the practitioner, Orbit Co's board is the responsible party for the covenant calculations, and the bank is the intended user.
Subject matter: Orbit Co's covenant calculations.
Criteria: the covenant terms set out in the loan agreement, which are specific and capable of being applied consistently.
Evidence: the tests the firm performs to obtain sufficient appropriate evidence on the calculations.
Assurance report: the written opinion issued to the bank on compliance with the covenants.
Level of assurance: the level depends on the scope of the procedures and the form of the conclusion, not simply on the fact that tests are performed. Here the engagement is designed to give reasonable assurance, so the work is extensive enough to support a positive opinion. This is a reasonable assurance engagement. If the scope were narrower and the conclusion were negative (for example, "nothing has come to our attention"), it would be limited assurance.

Answer: All five elements are present, so this is an assurance engagement: practitioner, board and bank; covenant calculations; loan agreement terms; evidence from the firm's tests; and a written opinion. The level is reasonable assurance, because the engagement is designed with a scope that supports a positive form of conclusion.

Example 2

Ravi & Co is asked by a client to (a) prepare the client's tax computation and (b) perform specified procedures on trade receivables and report the findings only, with no opinion. Explain whether each is an assurance engagement.

Show the solution

For (a): preparing a tax computation is a service where the practitioner produces information or advice. No conclusion is given to users about a subject matter against criteria, so it is not assurance.
For (b): the procedures are agreed in advance and the firm reports factual findings only. There is no conclusion that increases user confidence.
Users of the findings draw their own conclusions from them.
The missing element in both cases is the assurance report containing a conclusion.

Answer: Neither is an assurance engagement. (a) is a non-assurance tax compliance service. (b) is an agreed-upon procedures engagement, a related service, which gives findings but no conclusion.

Exam tips

OT case questions may ask which element is missing, so check for the conclusion first, then criteria. Constructed response questions may require you to explain the elements in the scenario.
Name the actual parties from the scenario. Generic answers lose marks in constructed response questions.
Use the exact terms: responsible party, intended users, subject matter, criteria. Examiners look for them.
Remember that objective test questions are all or nothing, so read each option fully before choosing. Watch for wording such as absolute or guarantee.
When contrasting assurance with non-assurance, state the reason: a conclusion is given or it is not.

Introduction to Assurance Engagements in other exams

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

Introduction to Assurance Engagements: frequently asked questions

What is an assurance engagement in ACCA?

It is an engagement where a practitioner obtains evidence and gives a conclusion that increases the confidence of intended users about a subject matter, evaluated against criteria. An audit of financial statements is the main example. It must be performed by an independent practitioner.

What are the five elements of an assurance engagement?

They are a three-party relationship, an appropriate subject matter, suitable criteria, sufficient appropriate evidence, and an assurance report containing the conclusion. All five must be present. If one is missing, the work is not an assurance engagement.

What is the difference between assurance and non-assurance engagements?

Assurance engagements end with a conclusion that gives users confidence. Non-assurance services, such as tax advice and consultancy, do not. Related services, such as compilation and agreed-upon procedures, also give no assurance. In these the practitioner provides advice, information or findings only.

Can an assurance engagement give absolute assurance?

No. The highest level is reasonable assurance, which is high but not absolute. Inherent limitations such as testing on a sample basis and the use of judgement prevent certainty.