While performing fieldwork for an assurance engagement, a member of the internal audit team identified...

When a key control is identified during fieldwork that was not recognized during the planning phase, it is critical to update the audit work program to include tests for this newly identified control. However, this adjustment should be made with the approval of the engagement supervisor. This ensures that the changes are properly documented and that the scope and objectives of the engagement remain aligned with the overall audit plan. Additionally, obtaining approval from the engagement supervisor maintains the integrity and oversight of the audit process.

The Institute of Internal Auditors (IIA) Standard 2240 – Engagement Work Program: "Internal auditors must develop and document work programs that achieve the engagement objectives."

IIA Practice Guide on "Engagement Planning"