Compiling financial statements represents the most basic level of service CPAs provide with respect to financial statements. In a compilation, the CPA must comply with certain basic requirements of professional standards, such as having a knowledge of the client's industry and applicable accounting principles, having a general understanding of the nature of the client's business transactions, the nature and extent of accounting records maintained, the qualifications of the accounting personnel responsible for the accounting process, and the accounting basis on which the financial statements are to be presented, as well as the form and content of the financial statements. The CPA must carefully read the financial statements to determine whether there are any obvious departures from applicable accounting standards or generally accepted accounting principles. It may be necessary for the CPA to perform "other accounting services" - such as creating your general ledger, or assisting you with adjusting entries for your books - before the financial statements can be prepared.

Upon completion, a report on the financial statements is issued that states a compilation was performed in accordance with professional standards, but no assurance is expressed that the statements are in conformity with applicable accounting standards or generally accepted accounting principles. This is known as the expression of "no assurance", compared to the "positive assurance" by an audit or the "limited (negative) assurance" by a review. A compilation service is required where small businesses wish to have the CPA prepare the financial statements in a professional way or the users do not need higher level of any assurance on the reliability of the financial statements.