Live in two states (CA/ NC) but work in NC. Residency question?

[winniey]

I live in CA/ NC and work in NC in 2019.  I moved to NC in late 2018 due to job assignments. Once assignment is done, I will move back CA. During weekdays, I work and stay in NC - apartment. I travel to CA every 2 weeks and visit my family. 

My primary source of income is earned from NC. I have a property (permanent home with mortgage) in CA and my family still lives in there. My driver license and car license plate are still in CA. I don't have any NC ID or driver license.

1). My bank accounts are in CA and I received 1099-misc (referral bonus) from bank which indicates box 17 state/ payer's state no= CA. Is that considered as earned income from CA? 

2). I filed 2 tax returns in 2018 due to relocation from CA to NC. Do I need to file multiple tax returns in CA and NC in 2019? What is my state of residence ? 

3). Am I considered as resident, non-resident, part time resident in NC tax returns? 

4). Can I file NC state tax returns with CA driver license? 

5). Can I still claim the mortgage interest deduction and property tax in Federal Tax Returns/ NC tax return even though my property is in CA? 

[MaryK4]

Because you are maintaining your California residency by keeping you driver's license etc. and you intend to return to California, your domicile is California so you are a California resident.

You will want to file a North Carolina nonresident tax return and a California resident state return.  You will report the NC income on the NR NC return.  If the referral bonus was related to your work in NC, you will want to include that as well.  After you do the NC NR state return, do the CA return and you will be able to claim a credit for the income tax you paid to North Carolina.You will claim the mortgage interest and property taxes on the California tax return.

[winniey]

In 2018 NC tax returns, I considered myself as part-time resident in NC but I never had NC driver license/ID. What can I do? Do I need to amend the NC/ CA tax returns for 2018? 

In 2019 tax returns, 

State of residence = CA

Lived in another state in 2019 = Yes/ No? 

[MaryK4]

If you considered yourself a NC resident, you would not have to amend for 2018, but for 2019 I would report as California resident- you would have to still file the NC NR though.  This question is about the state residency so it is a bit confusing.

@winniey