@hijyoon ,
(a) On your question of Self-employment taxes levied by both South Korea ( your tax home ) and USA ( your citizenship home ), please see details here --> Totalization Agreement with Korea | International Programs | SSA
(b) On your US taxes on self-employment / sole-proprietor earnings in Korea --
1. You do have to file US tax return for each calendar year -- US federal return on form 1040. TurboTax is quite capable to help you prepare and file the return.
2. Since your tax home is Korea, you can take advantage of Foreign Earned Income exclusion -- FEIE -- on your Korea sourced income.
(A) You do this by first preparing a Schedule-C ( sole Proprietor / self-employed ) covering your income in Korea. Note here that this is prepared per US tax laws i.e. you start with your gross income and you report all deductions/expenses per US rules which may or may not be the same the ones for Korea. You can download a copy of Schedule-C ( see here -- 2024 Schedule C (Form 1040) ) and instructions for the same here ---2024 Instructions for Schedule C (2024) | Internal Revenue Service.
(B) Next you go the incomes section of TurboTax, choose " I will select what I work on " and then from the list of income categories, select " Foreign Earned Income Exclusion ". This would walk you through a series of screens for filling out form 2555. Note here your foreign sourced income is the net income from schedule-C -- just make sure that this is not double counted.
(C) the net result of this should show on your form 1040 -- your schedule-C income under business income and then the excluded income --- See Schedule--1 --( lines 3 for business income and line 8 d for form 2555 mediated exclusion amount) --- > 2024 Schedule 1 (Form 1040).
Hope this helps in your preparing and filing your 2024 return.
Note that this is best done using windows downloaded TurboTax -- my favorite being Home & Business.
From your post I am not clear if you needed help only on the 2024 return or did you need to go back all the way to 2020.
Is there more I can do for you ?
