It is acceptable for an IS auditor to rely on a third-party provider's external audit report on service level management when the scope and methodology meet audit requirements. This means that the external audit report covers the same objectives, criteria, standards and procedures that the IS auditor would use to assess the service level management. This way, the IS auditor can avoid duplication of work and reduce audit costs and efforts. The service provider's certification and accreditation, the report's confirmation of service levels and the report's release date are not sufficient to justify reliance on the external audit report. References: CISA Review Manual (Digital Version) , Chapter 2, Section 2.3.3.