SA-505 "External Confirmation" states that design and way of a confirmation request may directly affect the confirmation response rate, and the reliability and the nature of the audit evidence obtained from responses.

The following factors should be considered while designing a confirmation request:-

(i) The assertions being addressed.

(ii) Specific identified risks of material misstatement, including fraud risks.

(iii) The layout and presentation of the confirmation request.

(iv) Prior experience on the audit or similar engagements.

(v) The method of communication.

(vi) Management’s authorisation to the confirming parties to respond to the auditor. Confirming parties may only be willing to respond to a confirmation request containing management’s authorisation.

(vii) The ability of the confirming party to provide the requested information.