When concerned about whether a transaction is recorded in the correct period, the internal auditor should consult accounting principles, standards, and relevant guidelines to determine the appropriate timing of the entry. External auditor approval does not negate the internal auditor's responsibility to ensure that the transaction complies with established accounting standards and principles. Consulting the relevant guidelines provides an objective basis for assessing the accuracy of the transaction's recording.
Reference:
The Institute of Internal Auditors (IIA) Standard 1220 - Due Professional Care: "Internal auditors must apply the care and skill expected of a reasonably prudent and competent internal auditor." Generally Accepted Accounting Principles (GAAP) or International Financial Reporting Standards (IFRS) depending on the applicable framework.