The nine stages of an assurance engagement
Assurance engagements can be typically broken up into nine stages. Not all stages will be clearly separated and identifiable in every engagement. Some stages, such as the engagement letter, may not be required during internal assurance, while others, such as problem-solving phase, may not be necessary in some external engagements.
| Please note: While these stages can apply to many forms of assurance, this guidance has been written primarily to explain the process associated with the use of ISAE 3000 (Revised) in assurance engagements. |
- Stage 1: What is assurance?
Gives an overview of what assurance is, and the possible triggers that should lead an individual or organisation to consider whether more assurance is needed. - Stage 2: Define the problem
A discussion on diagnosing the nature of the problem, and identifying exactly where increased credibility could add value. - Stage 3: Possible solutions
Reviews solutions that would lead to increased credibility, both in the form of internal and external assurance services and of other ways to gain comfort over information. - Stage 4: Assurance decision
Reviews in more detail the various different kinds of professional assurance service that can be obtained to build credibility. - Stage 5: What is feasible?
Discusses the practical questions that need to be answered to determine the potential scope of an assurance engagement. - Stage 6: Costs and benefits
Reviews the costs and benefits of different approaches to gaining or providing assurance. - Stage 7: Engagement letter
Sets out what should be expected from an engagement letter which forms the contractual basis for an external assurance engagement. - Stage 8: Fieldwork and analysis
Discusses the practicalities of the fieldwork and analysis undertaken to generate the substantive evidence that is necessary for a reliable, high quality assurance engagement. - Stage 9: Reporting
Discusses the nature and contents of an assurance report, and any other forms of reporting such as a management letter provided at the end of the engagement.
Please note: To be compliant with ISAE 3000 (Revised) all reports must cover a number of basic elements prescribed by the standard.
ICAEW's assurance resource
This page is part of ICAEW’s online assurance resource, which replaces the Assurance Sourcebook.