Try it out and then register a business?

First of all, you need permission from your parents and the family court.

If your parents agree, you must submit an application to the family court (formerly known as the guardianship court). This application is informal, meaning there are no pre-defined forms or anything similar to fill out. The application describes the minor's (ie, you) desire to become self-employed. The application must be signed by your parents.

Once the permit is granted, you, or your parents for you/with you, must register your commercial activity with the relevant municipality and tax office in accordance with Section 138 of the Fiscal Code (AO) and Section 14 of the Trade Code (GewO). For the latter, you must complete a tax registration questionnaire (FsE) and submit it electronically.

The tax office will then check your entries and assign you a tax number.

If you expect sales of more than €22,000, the small business regulation under Section 19 of the German Value Added Tax Act (UStG) does not apply. If you are not a small business owner, you must submit your advance VAT return to the tax office on the 10th day after the end of the advance VAT return period.

No matter what happens in the end, you have to have your parents submit your income tax return and form EÜR every year, and depending on the tax office's approach, also the trade tax return and VAT return.

If you do not register your business with your parents, this is an administrative offense and the tax office will not find this funny.

Why do your parents always have to be on board?

The legal basis is Section 112, Paragraph 1 of the German Civil Code (BGB). According to this, a minor requires the consent of their legal guardian(s), usually their parents, as well as the approval of the guardianship court, to pursue a self-employed business.

As you can see, it's not just a matter of trying it out.

But: The trade office charges about €25, while the tax office is free. After that, you won't have any further costs.