I'm working for a small US company remotely from Japan. The company doesn't have a branch in Japan or anything, so American social security tax is still being deducted from my paycheck (payroll is all done under an American address)
However, since I don't have any plans to move back to the US in the next 5 years, and Japan and the US have a totalization agreement for social security, I should be paying the tax in Japan, and not the US (according to my research from Googling & from talking to the social security information desk in Japan). Currently I'm paying in both countries.
I can't seem to find any resources that explain what I need to do to stop paying social security in the US. What kind of paperwork needs to happen? Is it even possible when it's a small company with no Japanese branch?