Illinois state tax paid when I lived in a foreign country the entire year of 2020

[lfvc2000]

I lived in a foreign country for the entire year while my wife lived in Illinois.  Based on Turbotax advice, I can file federal tax jointly and IL state tax separately.  Turbotax tells me I don't need to file IL state tax.  However, I have paid estimated tax for 2020 - how can I get the money back if I don't file IL state tax.  In addition Turbotax showed much small amount refund than the estimated tax I have paid - even if I file the IL state tax.  Anyone can help me to clarify what to do?  I have small pension from the company in IL that I retired from, I also have some income from IL, however, most of my incomes are from dividends and interests, do I still have to the dividends and interests incomes to IL when I lived in a foreign country.  I understand I may have to pay IL tax for the incomes from IL.   Does Turbotax program have consider this situation?  (I cannot take dividends/interests income out of my Federal income tax mock filing for IL State tax preparation, can I? Just for the purpose of calculating IL state tax I owe?)  Please advise.  Thanks.

[pk]

@lfvc2000 ,   if you did not have much foreign earned income AND you did not take any steps  to give up your IL residency  then for IL purposes you would still be "significantly" connected to IL -- your home is IL, your  family is in IL and you intended to return to IL after your sojourn abroad.  Additionally most of your income ( interest , dividend, pension  etc. ) are  essentially passive and  generally will be sourced to IL.  And you clearly recognized IL as a source state by estimated  tax payment.  Hence I see no real advantage in NOT filing as MFJ ( Married Filing Joint ) for IL taxes.   Now if you had a lot of foreign active income ( wages/ self-employment  etc. )  then  there could be  a benefit in keeping that foreign income  out of IL by not filing an IL return and allowing the Interest and dividend income ( probably jointly owned by you and your spouse)  and therefore the estimated tax payments  to be recognized by your spouse ONLY.

Does that help or do you need more --- in which case please provide answers to -- (a) quantum of foreign earned/self-employment income; (b) which country;  (c) when did you arrive in foreign country and when did you arrive back in the USA;  (d) did you try and exclude the foreign income from US taxes  etc. etc.;  (e) did you pay any foreign taxes on the income ( if )