"...I'm about to file for residency here in March..."
Residency for state income taxes isn't something you "file for". It's determined by state law. North Carolina Statute 105-153.3 defines "resident" as follows:
Resident. – An individual who is domiciled in this State at any time during the taxable year or who resides in this State during the taxable year for other than a temporary or transitory purpose. In the absence of convincing proof to the contrary, an individual who is present within the State for more than 183 days during the taxable year is presumed to be a resident, but the absence of an individual from the State for more than 183 days raises no presumption that the individual is not a resident. A resident who removes from the State during a taxable year is considered a resident until he has both established a definite domicile elsewhere and abandoned any domicile in this State. The fact of marriage does not raise any presumption as to domicile or residence.
https://www.ncleg.gov/enactedlegislation/statutes/pdf/bysection/chapter_105/gs_105-153.3.pdf
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
