Thanks. I reviewed the instructions for Form 8833 and see that report is specifically required when: "That a treaty modifies the amount of business profits of a taxpayer attributable to a permanent establishment or a fixed base in the United States"

The only thing I'm not sure on is Box 2 on the Form 8833 "List the Internal Revenue Code provision(s) overruled or modified by the treaty-based return position" Any idea what IRC provision relates to taxation of business profits?