Assurance engagements: CPA's provide a variety of services, they tend to be customised (unlike the structure of auditing). Can test financial and non-financial information. CPA's test the validity of past data of the business cycles.

Non-assurance engagements: Both engagements have rhe primary purpose of improving the quality of information. These engagements provided by CPA's include accounting and book-keeping services, tax services and management consulting services -- these fall outside assurance engagements.