Manuals

•  Submitting a return step by step 2025 (PDF, 3.34 MB) (in French)
•  Identifying via itsme (PDF, 356.25 KB) (in French)
•  How to use Biztax electronic mandates (PDF, 1.33 MB) (in French)
•  Creating the return of a company dissolved without liquidation (mergers and split-ups) (PDF, 171.48 KB) (in French)
•  Acknowledgement of receipt: what to do when receiving the message “Validity of the document certification unknown. Impossible to identify the author” with a yellow question mark? (PDF, 381.13 KB) (in French)
•  Compulsory configuration of your MAC when using Biztax (PDF, 345.7 KB) (in French)

FAQ

• General information
• Frequent error messages
• Characteristics

Tax information

•  Tax Shelter approved audiovisual works and Tax Shelter approved scenic works - Rates of corporate income tax and non-resident income tax as regards the companies on previously exempted profits (PDF, 97.41 KB) (in French)
•  Income tax on legal entities assessment year 2021 - Deductible costs of a building located in Belgium (PDF, 96.58 KB) (in French)