Group 1 - The article discusses the process for individual taxpayers with multiple sources of business income to file an annual consolidated tax return by March 31 of the following year [1] - It provides a step-by-step guide on how to fill out the Business Income Tax Return Form (C Form) through the individual electronic tax bureau web portal [3] - The article emphasizes the importance of selecting the correct tax management authority for the consolidated declaration [3] Group 2 - The article references previous recommendations on how to submit the Business Income Tax Return Form (B Form) through the electronic tax bureau [5] - It highlights that the platform is a non-official resource aimed at providing learning materials and is not a standard for actual tax filing [8] - The article encourages readers to engage in sharing learning experiences and outcomes [8]