ISA 210, discusses the responsibilities of the auditor to agree on the terms of the audit engagement with management and, where appropriate, those charged with governance of the entity.
The auditor aims to accept or continue an audit engagement only when agreed on the premise that the audit be performed by:
(A) determining whether concur prior to an audit conditions; and
(B) confirmation that there is a common understanding by the auditor and management and, where appropriate, those charged with governance of the entity about the terms of the audit engagement.
Pre-audit compliance requirements: it must determine whether the financial information prepared is acceptable. Obtain the agreement of management and government officials. Read the rules if limitations on the scope of the audit imposed prior to acceptance of the audit.
According to the terms of the audit engagement: the content of the letter of appointment must be regarded as established by ISA 210 ap.9-12 (sample letter in Annex 1 of the NIA).
Recurring audits: the auditor assess whether the revised terms custom is needed and if necessary remind the entity.
Changing the terms of the audit engagement: the modification of the terms of the orders can only be changed if there is reasonable justification.