Tax evasion is one of the world's societal problems, which annually contributes to distorted competition when large tax amounts disappear from welfares. High-income earners and companies have managed to minimize tax expenditures through systematic applications, which has been revealed recently by elements such as Panama Papers, Luxleaks and Swissleaks. Previous studies have highlighted a problem that clear boundaries between tax planning and tax evasion do not exist. Whether or not which tax techniques and methods that are compatible with the law has been expressed as a difficulty in understanding the profession of accountants but also in professions such as tax advisers and accounting consultants. The purpose of the study was to investigate how auditors handle the issues regarding the gray zones between tax planning and tax evasion. The study's intention was to review previous legal cases and companies' audit reports to see how auditors have acted and how the court assessed complex legal cases, which were then supplemented with an interview study. This because when reviewing the cases, attention was drawn to the results that led us to interviews in order to take part in the auditor's perspective on the matter. The study was based on a qualitative research method where the results showed that auditors should consult more complex tax procedures with other auditors and tax lawyers to avoid legal consequences. The results further showed how important it is for auditors to keep constantly updated by legislation and regulations as these tend to change over time. The result also showed that auditors should act restrictively and judiciously and have a strict attitude in their working methods for minimizing undesirable situations where irregularities can occur. Auditors must also have a well-designed audit plan to avoid the risk of material errors slipping through the audit.