Dual status questions

[LondonSam26]

Hi, first time posting so I hope this is OK (I couldn't find specific answers anywhere else). I've been tearing my hair out trying to understand how to file and keep getting conflicting advice.

Essentially I lived in the US for the first 3 months of 2020, and then moved back to the UK. I understand I need to file two returns, a 1040 for the first three months and then a 1040NR for the remaining 9.

TT recommended Sprintax for the NR but Sprintax told me quite bluntly not to use them, confusingly. So I'm going to have to do this myself. On the 1040NR I believe I only have bank interest and dividends (which shouldn't be taxable anyway?). But I also need to add schedule NEC, schedule OI, and form 8840. Have I missed anything there?

For the 1040, TurboTax is confusingly telling me to take the standard deduction, although I believe I can't do this as a dual status? Should I continue with itemised deductions and then do the Foreign Earned Income Exclusion for everything I earned in the UK? (I'm counting my tax residency to end in March when I left).

Finally, for (California) state taxes, I only need to file one return I believe - should this be the 540 or 540NR though? I've heard. conflicting advice on whether I became CA non-resident when I left or whether it counts as resident all year regardless.

Would really appreciate any answers and advice here...!

[ErnieS0]

We'd have to know more about your situation, specially what type of visa you had, how long you were in the U.S. prior to 2020 and what type of income you had in the U.S. and U.K.

You would be dual-status if you were a U.S. resident at the time you left and had U.S. source income during your period of non-residency.

Your U.K. income would not be subject to U.S. income tax if it was not effectively connected with a U.S. trade or business. If it were effectively connected, would not qualify for the foreign earned income exclusion unless you are a U.S. citizen or resident alien.

Bank interest is not taxable to a nonresident if it is not effectively connected with a U.S. trade or business. 

Dividends are taxable during the nonresident period if they are paid by U.S. companies or paid by a foreign corporation if at least 25% of the corporation's gross income is effectively connected with a U.S. trade or business for the three tax years before the year in which the dividends are declared.

Nonresident Aliens - Source of Income

You would be a part-year California resident unless you are on an overseas employment contract lasting less than 546 days. In such case, California may consider you to be a full year resident.

2020 Guidelines for Determining Resident Status

[LondonSam26]

Thanks, Ernie. Really appreciate your reply. I was resident in 2019 too on an L visa, so I'm fairly sure the dual status is the way forward.

Just to be clear - TT is still recommending I take the standard deduction, which I believe I cannot do, right? Should I just override this with itemised, or do I need to tell the software somewhere this is a dual return (as I guess it hasn't recognised this). Thanks. 

[LinaJ2020]

As TurboTax is designed for US citizens or residents to file their taxes, it would not recognize you are a dual status taxpayer, unfortunately.

To change from standard deduction to itemized, do not override.  Follow steps here to switch:  Standard to Itemized

@ LondonSam26