After three years of successfully running a business and fulfilling all the requirements, you can apply for a permanent resident permit. After granted a permanent resident permit, your residence in Germany is no longer binding with your business. You can take up your other occupation as well.
How long do I have to keep my business running to maintain my status in Germany?
I am interested in applying for a German residence permit for the purpose of self-employment. I understand that the initial permit is only valid for 3 years and upon expiration I might be able to get a settlement permit as long as the proposed business plan is successfully fulfilled. I assume that I would have to keep the business running before a settlement permit is granted. But what about after that? Can I sell my business after I get a settlement permit? Or do I have to wait until a citizenship is granted?