I second that. There is no need to start a UG or GmbH. Especially not for avoiding personal liability! Because as the director of the company (which you are a

I second that. There is no need to start a UG or GmbH. Especially not for avoiding personal liability! Because as the director of the company (which you are as a solo founder), you ARE still personally liable (GmbH-Geschäftsführer-Haftung). Get a Gewerbeschein. It's 25€ or so. IHK might want membership fees, but they are really low if you don't have much income. Go with Kleinunternehmerregelung. It makes many things easier if your revenue is below 17,500€ per year. Don't forget: The first 8,000€ in income per year are tax-free.