Am I required to file a state tax return in Oklahoma, even if I am a bona fide resident overseas?

[Mildly-Confused]

I filed a Federal income tax return for 2016 and claimed the bona fide foreign residence (and it was accepted).

However, while I am abroad long-term I have a tie to Oklahoma (driver's license, bank account, my foreign university considers Oklahoma to be my domicile).

I did not file a state return in OK because I had no income there.

I was not aware, when I filed my 2016 federal return, that I could possibly be required to file a state return in Oklahoma as well.

But now looking at the rules, I am confused.  It seems like I might have to file a state return, but I can't figure out anything for certain. I am not sure where I will be living in a few years time, whether it be abroad or in the US, but I don't intend on living long-term in Oklahoma, at all. But I always have family whose doors are open to me in Oklahoma and right now my university overseas has my home address on file as my OK address. But in the literature they do not mention Oklahomans living abroad, so I don't know if I am a resident, non-resident, or what?

Furthermore, I cannot find out anywhere if OK allows for the foreign earned income exclusion. It is in none of the legislation that I can find. Do they?

If I find out I should have filed a return, how bad is it that I am now so late for 2016? If I have to file I obviously will - better late than never! But it would be an honest mistake on my part as I didn't know about the possibility of a filing requirement until now, but I've never filed a late return before so I don't know what could happen.

UPDATE: I spoke with the Oklahoma Tax Commission in person and they determined that OK is NOT my domicile. The adviser looked at my situation and determined that I had more of a domicile overseas, and my accountant determined the same. She said I could keep my OK drivers license and still have the domicile overseas. For them, it seems like residency = domicile, so if I am resident overseas, my domicile is NOT Oklahoma. I may have understood that wrong, but I had two advisers and my accountant tell me this.

I decided to edit this in case anyone else has a similar issue: go talk to the OKC tax commission -- they will sit down and help you.

[MichaelL1]

If you are a resident of OK (which it appears you are from the driver's license and the domicile), you are required to file a resident return for OK even while overseas.

"Filing Requirements. Tax Year 2016. Oklahoma resident individuals are required to file an Oklahoma income tax return when they have sufficient gross income to file a Federal income tax return. "

Source: https://www.ok.gov/tax/Individuals/Income_Tax/Filing.../General_Information/

Resident... An Oklahoma resident is a person domiciled in this state for the entire tax year. “Domicile” is the place established as a person’s true, fixed, and permanent home. It is the place you intend to return to whenever you are away (as on vacation abroad, business assignment, educational leave or military assignment). A domicile, once established, remains until a new one is adopted.

the OK tax return (Form 511 part I) starts from the Federal Adjusted Gross Income (line 37) which is after the Foreign income exclusion is taken. 

So it is very possible you may have a zero State tax liability, however you are still required to file, due to your gross income exceeding the OK filing requirement.

https://www.ok.gov/tax/documents/511Pkt-17.pdf  (for 2017 tax year, however same rules apply to 2016)

Penalties are based on tax due, so if no tax is due to OK then there would be no penalty. 

[Mildly-Confused]

See my edit. Apparently it seems like it is more of a case by case issue. The driver's license didn't seem to matter very much to the tax adviser, nor did the bank account.

[MichaelL1]

Thank you for the Update to your question, as I based my answer on where you left and where you are planning on returning.  I would document the answer from the OK Tax Commissioner (with date, and who you talked to -if possible) and file it with it your tax records, should any questions be raised at a later date.  Thank you for the additional information.

[Mildly-Confused]

That's a very good idea. I plan on calling them next week to clarify a few things and keep some record of this with my tax stuff. What do you mean you based your answer on where I left and where I was planning on returning? I intend to retain my US citizenship and probably will be able to get a job in the US but I don't plan on living or working in OK.

[MichaelL1]

For domicile OK does look at where you plan on returning to at the end of the overseas assignment, and if in your case it is not OK, then no worries.

[Mildly-Confused]

Ah, I'm not on an overseas assignment: I moved overseas a few years ago to go to graduate school, and am still in graduate school.

[MichaelL1]

Sorry, it would then be "overseas education" versus "overseas assignment"