As the question stipulates. If a US citizen living in the USA wants to work for a foreign company he owns and that has no US entity. Is this legal?
He would basically be in a situation where he's doing everything as if he were residing in that foreign country but simply residing in the USA.
I know that the US consider taxable income to be income generated on american soil. So filing taxes in the US would be a requirement. But is the setup even legal? Or is it an obligation for the foreign entity to open a US entity and pay through it?