Section: Volume E

Internal auditors can rely on the work of other assurance providers, including internal compliance teams, to expand their audit coverage efficiently. This practice is based on the principle of leveraging existing assurance functions within the organization to avoid duplication of efforts and to use resources more effectively. By relying on the work performed by compliance teams, internal auditors can ensure comprehensive coverage without necessarily increasing the direct audit hours. However, it is crucial that the internal auditors evaluate the competence and objectivity of the compliance teams and ensure that their work meets the required standards before relying on it.
The Institute of Internal Auditors (IIA) Standard 2050: Coordination and Reliance IIA Practice Advisory 2050-2: Relying on the Work of Other Assurance Providers

The chief audit executive (CAE) is accountable for ensuring that adequate support exists for the conclusions and opinions formed by the internal audit activity. When relying on the work of external auditors, the CAE must ensure that the work is sufficient and appropriate to support the internal audit conclusions. This involves reviewing the external auditors' work to confirm its relevance and reliability, and integrating it into the internal audit processes as necessary.
References:
* The Institute of Internal Auditors (IIA) Standard 2050 - Coordination and Reliance.
* IIA Standard 2340 - Engagement Supervision

Section: Volume A