According to the International Professional Practices Framework (IPPF), issuing an interim report is appropriate for keeping management informed of audit progress, especially when audit engagements extend over a long period of time, and for communicating any significant changes in the scope of the engagement. Interim reports serve as a means of maintaining transparency with management and ensuring that any adjustments to the audit plan are communicated promptly.
IIA Reference:
IIA Standard 2440: Disseminating Results allows for interim reporting when there is a need to communicate significant findings or changes in scope before the final report is issued. This ensures that management remains informed of critical issues that may impact the audit or the organization.
The Practice Guide on Communicating Interim Results suggests that interim reports are useful for providing updates during long engagements or when there are significant changes in the engagement's scope that management needs to be aware of.