31. On recurring audits, should the auditor obtain a new audit engagement letter each period?

While not required, changes in circumstances may make it appropriate to revise the terms of the audit engagement or remind the entity of existing terms. For example, paragraph A28 of Canadian Auditing Standard (CAS) 210, Agreeing the Terms of Audit Engagements, includes the following factors that may make it appropriate to revise the terms of the audit engagement or to remind the entity of existing terms:

• Any indication that the entity misunderstands the objective and scope of the audit.
• Any revised or special terms of the audit engagement.
•  A recent change of senior management.
• A significant change in ownership.
• A significant change in nature or size of the entity's business.
• A change in legal or regulatory requirements.
• A change in the financial reporting framework adopted in the preparation of the financial statements.
• A change in other reporting requirements.