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The Institute of Internal Auditors North AmericaBreadcrumb SeparatorStandards and GuidanceBreadcrumb SeparatorMandatory GuidanceBreadcrumb SeparatorStandards With Introduction

2017 Standards | Introduction | Attribute Standards | Performance Standards | Glossary

​Introduction to the Standards

Internal auditing is conducted in diverse legal and cultural environments; for organizations that vary in purpose, size, complexity, and structure; and by persons within or outside the organization. While differences may affect the practice of internal auditing in each environment, conformance with The IIA’s International Standards for the Professional Practice of Internal Auditing (Standards) is essential in meeting the responsibilities of internal auditors and the internal audit activity.

The purpose of the Standards is to:

  1. Guide adherence with the mandatory elements of the International Professional Practices Framework.
  2. Provide a framework for performing and promoting a broad range of value-added internal auditing services.
  3. Establish the basis for the evaluation of internal audit performance.
  4. Foster improved organizational processes and operations.

The Standards are a set of principles-based, mandatory requirements consisting of:

  • Statements of core requirements for the professional practice of internal auditing and for evaluating the effectiveness of performance that are internationally applicable at organizational and individual levels.
  • Interpretations clarifying terms or concepts within the Standards.

The Standards, together with the Code of Ethics, encompass all mandatory elements of the International Professional Practices Framework; therefore, conformance with the Code of Ethics and the Standards demonstrates conformance with all mandatory elements of the International Professional Practices Framework.

The Standards employ terms as defined specifically in the Glossary. To understand and apply the Standards correctly, it is necessary to consider the specific meanings from the Glossary. Furthermore, the Standards use the word “must” to specify an unconditional requirement and the word “should” where conformance is expected unless, when applying professional judgment, circumstances justify deviation.

The Standards comprise two main categories: Attribute and Performance Standards. Attribute Standards address the attributes of organizations and individuals performing internal auditing. Performance Standards describe the nature of internal auditing and provide quality criteria against which the performance of these services can be measured. Attribute and Performance Standards apply to all internal audit services.

Implementation Standards expand upon the Attribute and Performance Standards by providing the requirements applicable to assurance (.A) or consulting (.C) services.

Assurance services involve the internal auditor’s objective assessment of evidence to provide opinions or conclusions regarding an entity, operation, function, process, system, or other subject matters. The nature and scope of an assurance engagement are determined by the internal auditor. Generally, three parties are participants in assurance services: (1) the person or group directly involved with the entity, operation, function, process, system, or other subject matter — the process owner, (2) the person or group making the assessment — the internal auditor, and (3) the person or group using the assessment — the user.

Consulting services are advisory in nature and are generally performed at the specific request of an engagement client. The nature and scope of the consulting engagement are subject to agreement with the engagement client. Consulting services generally involve two parties: (1) the person or group offering the advice — the internal auditor, and (2) the person or group seeking and receiving the advice — the engagement client. When performing consulting services the internal auditor should maintain objectivity and not assume management responsibility.

The Standards apply to individual internal auditors and the internal audit activity. All internal auditors are accountable for conforming with the standards related to individual objectivity, proficiency, and due professional care and the standards relevant to the performance of their job responsibilities. Chief audit executives are additionally accountable for the internal audit activity’s overall conformance with the Standards.

If internal auditors or the internal audit activity is prohibited by law or regulation from conformance with certain parts of the Standards, conformance with all other parts of the Standards and appropriate disclosures are needed.

If the Standards are used in conjunction with requirements issued by other authoritative bodies, internal audit communications may also cite the use of other requirements, as appropriate. In such a case, if the internal audit activity indicates conformance with the Standards and inconsistencies exist between the Standards and other requirements, internal auditors and the internal audit activity must conform with the Standards and may conform with the other requirements if such requirements are more restrictive.

The review and development of the Standards is an ongoing process. The International Internal Audit Standards Board engages in extensive consultation and discussion before issuing the Standards. This includes worldwide solicitation for public comment through the exposure draft process. All exposure drafts are posted on The IIA’s website as well as being distributed to all IIA institutes.

Suggestions and comments regarding the Standards can be sent to:

The Institute of Internal Auditors
Standards and Guidance
1035 Greenwood Blvd, Suite 401
Lake Mary, FL 32746 USA


An updated edition of the International Professional Practices Framework (IPPF) guide, more commonly known as the Red Book, is now available. Visit the IIA Bookstore for more information.