Hi, I did a bunch of reading and got some free advice from an expat tax attorney. It seems conclusive, unless you have formed a legal entity like an LLC or similar you do not have to file 8858. The clue is in the word "entity", no entity no 8858.
That's not what the Regulations say. The law changed on 22 December 2017. The relevant Regulations do not require an "entity". Because the IRS may take a different view than you or I on "all the facts and circumstances" a cautious approach is to file Form 8858. The definition in Treasury Regulations reads:
"g)Definition of foreign branch -
(1)In general. For purposes of this section, the term foreign branch means an integral business operation carried on by a U.S. person outside the United States. Whether the activities of a U.S. person outside the United States constitute a foreign branch operation must be determined under all the facts and circumstances. Evidence of the existence of a foreign branch includes, but is not limited to, the existence of a separate set of books and records, and the existence of an office or other fixed place of business used by employees or officers of the U.S. person in carrying out business activities outside the United States. Activities outside the United States shall be deemed to constitute a foreign branch for purposes of this section if the activities constitute a permanent establishment under the terms of a treaty between the United States and the country in which the activities are carried out. Any U.S. person may be treated as having a foreign branch for purposes of this section, whether that person is a corporation, partnership, trust, estate, or individual. "
