* First party audit or internal audit: Conducted internally by your own staff who are trained. It can also be performed by an external company.
* Second party audit or supplier audit: Conducted by lead auditors in your organisation. This is done to ensure your suppliers function properly and that you get the supply of products/services correctly. As internal audits, these can also be performed by external agencies if you don’t have the qualified resources.
* Third party audit or certification audit: This must be carried out only by auditors of Certification Bodies.
Depending on the documents submitted, an ISO audit for the business is conducted wherein the genuineness of the documents are checked. The authority then makes a decision based on the defined procedures.