Lived and earned income in both CA and NC states during the year, CA asks for additional tax payment on NC income, what should I do?

[phson01]

Dear experts, I really need help here on what to do for my situation, this is for my personal return filed through Turbotax back in 2015 tax year (sorry about the long post):

• I worked in two different states in 2015, received two separate W2's at the end of the year, one for my earnings while I lived in North Carolina (Jan to May), the other one was for my earnings while I lived in California (Jun to Dec). However, both W2s have my California address on, since I moved to California mid-year 2015, both W2's are mailed to my California address.
• I only filed the CA income W2 (June to December) with CA, not both W2s, because of the other W2 associated with my earnings while I was physically living in NC (January to May).
• CA Tax Franchise Board discovered the NC W2 and asked me to pay CA state income tax for my income earned in NC, because I have a CA address on it (which might caused them to mistakenly think I physically lived in CA for the whole year). 
• I talked to a specialist from CA tax agency on the phone a few months ago regarding this incident, and I was told to go back to my prior employer to re-issue my 2015 NC W2 with my NC address on it.
• I contacted my prior company's payroll and HR department, however, they told me they couldn't update my address on the 2015 W2, I should just file the NC W2 to NC regardless what's my address on it, don't file to CA, which was what I did.

CA is still asking for payment, and since NC state tax has already been withheld in my NC W2, paying CA again would result in paying double taxes on my NC income... what should I do here?

Thank you!

[SteamTrain]

Probably visit a local tax pro to get it straightened out and filed properly.  (and NOT one of those seasonal storefront operations)

I don't think your "advice" from the agent you talked to is correct (Unless you were a college student with a CA home address, but in NC just for college).  The address that is on the W-2 is immaterial.  What is important is which state you were a resident of at the time you earned the income. (but that's my non-professional opinion)

(Assuming you were not a CA resident, and not just in NC for college) …..What you "should" have done when you filed your 2015 taxes, was to have prepared and filed part-year tax returns for both NC and CA.   Both of those state Part-year tax returns would have started with BOTH W-2 forms entered as full-year income, but you would have allocated just the NC W-2 as NC-resident income, and just the CA W-2 as CA-resident income during their preparation.   IF you didn't do that, then yeah..CA might complain and come back at you, for not at least starting with both W-2 forms to indicate total yearly income.

You can't amend your 2015 state tax filings to correct things, unless you already have 2015 Desktop TTX installed on your home computer, with both states too, since the 2015 tax software and states and updates are no longer available.   (And I can't know if you really did it right anyhow...but from your explanation so far, doesn't sound like you prepared&filed the state forms properly).