The auditor needs evidence that the specific control—independent telephone verification of changed supplier bank details—actually operated for the transaction selected. Documentation of the call showing the parties involved and the information verified provides direct evidence that the prescribed procedure was performed. A supplier’s commercial registration confirms existence but does not demonstrate verification of bank-detail changes. Reviewing a subsequent payment and invoice may establish where funds were sent, but it does not prove that procurement contacted the supplier before changing the master data. Annual employee confirmations are less persuasive because they are generalized representations rather than evidence of the specific control instance being tested. Therefore, contemporaneous documentation of the verification call is the most relevant and persuasive evidence of the control’s operating effectiveness.