330 Day Rule

Hi all, I'm struggling to understand this. I'm a graduate student in the UK receiving a stipend, which is not taxable in the UK, but it appears I do have to pay tax on it in the US, unless I can show that I am 'resident' in the UK, which seems to mean at least 330 days of the year not in the US?? Same goes for waiving the penalty for not having US health insurance.

How exactly does one establish residency for this purpose if you still need to spend more than 35 days/year in the US? I paid rent on a flat in the UK for the entire year, but I did come back for several months over the course of the year (primarily to visit my long-distance, US based partner).  Do they really just count physical presence rather than other factors clearly showing my primary residence in the UK, like paying rent and utility bills? Has anyone ever had to prove this in an audit?

thanks for any advice!
Erin

You are correct that the United States charges tax on worldwide income. If you are thinking about electing to claim the foreign earned income exclusion for 2018; file Form 2350 to extend the filing date until 30 January 2020 - so you have a qualifying period of bona fide residence before you file.

Thank you! But am I correct in thinking that establishing residency to claim exclusion requires no more than 35 days physically absent from the UK in any given 360 day period? If that's true, I'm not sure how I'd ever establish residency, as I come back to the US for roughly two months each year....is there any way to claim residency by virtue of renting a flat and paying bills even when I'm away?