Thanks
@Marzio
I think the first thing to get clarity on︅ is whether PT would consider the US LLC a local tax resident.
For that we︆ would need to check what PT tax law says.
That piece of info I am︇ missing now
Now we'd have two scenarios:
1. PT does
NOT consider the US LLC︈ local tax resident
2. PT DOES consider the US LLC local tax resident
Under scenario 1 you are fine with PT. If the US LLC is single member and︉ not ETBUS, no tax in the US and you would have to analyze what happens︊ with other countries you'll be staying during the year.
Under scenario 2, the DTT would︋ play a role, theoretically. I still have doubts on this since the DTT is relevant︌ when a (legal) person is liable for tax in both signing states; a single member︍ US LLC is however a pass-through and disregarded entity in the US and you will︎ not get a certificate of tax residence from the IRS. If the US LLC is️ not a tax resident of the US then the DTT cannot help and you are on the hook in Portugal.
Even if the DTT were to be invoked, the PT-USA treaty reads as follows for PE:
Then there's a clause similar to the one you cite for Canada-PT:
But in my opinion this clause 4 does NOT mean that you need any of the points in clause 2 for 9 months. It just describes another situation in which you would trigger PE. I.e., even if you do not have any of a) to f) in 2. in PT, you can still trigger PE if for︀ instance you have employees working in PT from their home for over 9 months.
The way I see it, if you stay for a couple of months in PT and︁ you manage the US LLC from there, you are creating a PE in PT. Another︂ discussion is what part of the US LLC profits would be taxable in PT.
This reasoning would generally be applicable to other countries you stay in, so you'd be at︃ risk of triggering (partial) PE in all of them.