Generally, individual taxpayers use the calendar year as tax year: January 1 through December 31.
2 special cases:
Death of a resident: January 1 through the date of death
Resident who becomes a non-resident: January 1 through the date of leaving Korea
Under the 1994 tax reform, the individual income tax assessment system was converted into a self-assessment system under which each taxpayer is required to file a return and pay the proper amount of tax by the due date as prescribed by the individual income tax law.
Interim Prepayment for Global Income
As interim prepayment, a resident with global income is subject to pay an amount equivalent to half of the global income tax amount paid or payable in the preceding year, by the end of November.
"The income tax amount paid or payable in the preceding year" is the aggregate of the tax amount payable for interim prepayment in the preceding year, the tax amount finally payable and the amount of penalty taxed.
Final Return and Payment
1) Return on tax base
A resident who has global income, retirement income, capital gains or timber income in the taxable period is required to file a return to the superintendent of the competent district tax office in the place of tax payment within the period from May 1 to May 31 in the following the year concerned.
Tax returns are required to be accompanied by the following documentations:
- Documents certifying a person eligible for personal exemptions;
- Documents in which gross receipts and necessary expenses calculated are recorded;
In the case of persons who have real estate income, business income or timber income:
- balance sheet,
- income statement,
- a trial balance,
- and other required documents;
In the case where the gross receipt is less than 300,000,000 Won:
- the simplified income account statement;
- Particulars of tax free reserves;
Residents not liable for submitting final returns
The following residents are not liable to submit final returns:
A resident who has only:
- wage and salary income
- retirement income
- or both
- capital gains and has filed a preliminary return
A resident who has only:
- Interest income subject to separate taxation
- Dividend income subject to separate taxation
- Both of the above
- Or other income subject to separate taxation
National Tax Service
The South Korean National Tax Service (www.nta.go.kr/eng) provides you the possibility of filing your tax return online. You can download the necessary forms and get detailed instructions. They also operate a service telephone – both in English and Korean language – in case you need any further help.