This site uses cookies to provide you with a more responsive and personalised service. By using this site you agree to our use of cookies. Please read our cookie notice ( for more information on the cookies we use and how to delete or block them.
The full functionality of our site is not supported on your browser version, or you may have 'compatibility mode' selected. Please turn off compatibility mode, upgrade your browser to at least Internet Explorer 9, or try using another browser such as Google Chrome or Mozilla Firefox.

CAS 220, Quality Control for an Audit of Financial Statements

Ef­fec­tive date:

Ef­fec­tive for audits of financial statements for periods ending on or after December 14, 2010, ex­cept for sub­se­quent amend­ments.

[Cana­dian Au­dit­ing Stan­dard (CAS) 220, Quality Control for an Audit of Financial Statements, should be read in con­junc­tion with CAS 200, Over­all Ob­jec­tives of the In­de­pen­dent Au­di­tor and the Con­duct of an Au­dit in Ac­cor­dance with Cana­dian Au­dit­ing Stan­dards.]


This Canadian Auditing Standard (CAS) deals with the specific responsibilities of the auditor regarding quality control procedures for an audit of financial statements. It also addresses, where applicable, the responsibilities of the engagement quality control reviewer. It is to be read in conjunction with relevant ethical requirements.

Quality control systems, policies and procedures are the responsibility of the audit firm. Under CASs, the firm has an obligation to establish and maintain a system of quality control to provide it with reasonable assurance that: (a) the firm and its personnel comply with professional standards and applicable legal and regulatory requirements; and (b) reports issued by the firm or engagement partners are appropriate in the circumstances.  This CAS is premised on the basis that the firm is subject to CASs or to requirements that are at least as demanding.  

The objective of the auditor is to implement quality control procedures at the engagement level that provide the auditor with reasonable assurance that: (a) the audit complies with professional standards and applicable legal and regulatory requirements; and (b) the auditor's report issued is appropriate in the circumstances.

His­tory of CAS 220




August 2020

Para­graphs 9 and 10 were amended to reflect changes in the provincial Codes of Professional Conduct. See Completed Project.     

The changes are ef­fec­tive July 15, 2020.

April 2021

CAS 220 was revised as a result of the issue of the new Audit Quality Management standards. See Com­pleted Pro­ject.

The changes are ef­fec­tive for audits and reviews of financial statements for periods beginning on or after December 15, 2022 and for related services engagements on December 15, 2023.

Note: The above sum­mary does not in­clude de­tails of con­se­quen­tial amend­ments made as the re­sult of other pro­jects.


Amend­ments un­der con­sid­er­a­tion

  • None

Correction list for hyphenation

These words serve as exceptions. Once entered, they are only hyphenated at the specified hyphenation points. Each word should be on a separate line.