How to File Income Tax in South Korea
Filing deadline
The typical filing deadline in South Korea is 31 July, though extensions may be available depending on your filing method and residency status.
Who needs to file
- Employees whose only income is salary may have tax fully withheld by their employer and may not need to file separately, depending on local rules.
- Self-employed individuals, freelancers, and business owners generally must file an annual return.
- Anyone with additional income (investments, rental property, foreign income) should check local filing thresholds.
Steps to file
- Gather income statements (employer statements, invoices, investment income records) for the 2026 tax year.
- Determine your filing status and applicable deductions — see the deductions guide.
- Calculate taxable income and tax owed — use the calculator on this site as a starting estimate, and check the brackets guide for a worked example.
- Submit your return through South Korea's official tax portal or with a licensed preparer before 31 July.
- Keep records for at least the period required by local law (commonly 4–7 years).
What happens if you file late
Most tax authorities charge a late-filing penalty (often a percentage of unpaid tax, sometimes a flat fee) plus interest that accrues daily until the balance is paid. Filing on time even without full payment usually avoids the larger late-filing penalty, leaving only late-payment interest to deal with.
This is general guidance, not tax advice. Filing rules vary by residency, income type, and year — confirm details with South Korea's tax authority.