The ISSAIs are professional auditing standards and guidelines essential for enhancing the credibility, quality and professionalism of public-sector auditing. It was developed by INTOSAI to promote independent and effective auditing by member SAIs and support the members in development of their own professional approach on the basis of their specific national mandate.
The public-sector auditing are broadly classified under three main types: financial, performance and compliance auditing. Therefore, the ISSAIs set the requirements only for these types of audits. It does not provides the standards for carrying out investigations, reviews or other engagements which may be additional functions mandated by specific national laws and regulations of the respective SAIs.
The ISSAI framework consists of standards and guidelines. The ISSAIs form a hierarchy of official pronouncements with four levels.