I am going to be moving from Canada to Austria next spring. I hold both an EU citizenship and a Canadian citizenship. I currently operate as a sole proprietor in Canada. One of my clients wants to keep working with me when I move to Austria, as I can work remotely as a software developer. The catch is that he can only pay me if I invoice him as a Canadian company.
I know that I will need to register as "self-employed" in Austria, so that I can pay into social security and health care. My main question is: Can I continue to operate my sole proprietorship in Canada? If I maintain a Canadian address, can I just continue to bill him as I have been doing in the past? Will I need to continue charging him GST, even though the work is being performed from outside Canada? What will be my tax obligations to Canada?