In Switzerland, tax fraud occurs when a taxable entity attempts to deceive tax authorities using documents that are counterfeit or contain incorrect information, and this attempt results in the taxable entity paying less taxes than they are legally required to. Tax fraud is a crime. When a person or other entity commits tax fraud, they deliberately submit counterfeit documents or documents that contain incorrect information to the tax office. These may include salary statements, bank statements, business accounts, balance sheets, income statements, or other documents. Tax returns themselves do not qualify as documents in this regard.
Tax fraud is punishable with a prison term of up to 3 years or a fine of up to 360 daily payments.
If you do not submit counterfeit or incorrect documents, but end up paying less taxes than you are legally required to due to certain information being omitted, that it is not classified as tax fraud, but as tax avoidance.
If you have questions about your tax returns, it is best to contact your municipal or cantonal tax office directly.