At least in Germany, this means you will pay more taxes that you wouldn't otherwise, not that you would go to prison. I think it happens if more than 80% of you

At least in Germany, this means you will pay more taxes that you wouldn't otherwise, not that you would go to prison. I think it happens if more than 80% of your yearly revenue comes from a single client. You can always start a company and this is not a problem anymore.