The Millo Blog Editorial Team reviewed official guidelines from the National Tax Service (NTS) to verify these procedures. Updated July 20, 2026.
Depending on your employment status and sources of income, you will likely encounter one of two primary tax processes in South Korea: the year-end tax settlement (usually completed in February) or the Comprehensive Income Tax return (filed in May). Most foreign employees only need to complete the February settlement through their employer, but those with additional income streams—such as business earnings, dividends, or interest—must file a separate return in May to reconcile their total annual tax liability.
Do I need to file a tax return in Korea?
Whether you must file a return depends on your tax residency status and the type of income you earned during the previous calendar year. Generally, foreign residents are required to report income earned within Korea.
For most foreign workers (excluding daily workers), the process is simplified. If your only source of income is a salary from a Korean employer, the year-end settlement process handled by your company typically satisfies your filing obligations. However, you must file a Comprehensive Income Tax return if you fall into any of the following categories:
- You have aggregate income, which includes business income, interest, dividends, and wage/salary income.
- You earned income from multiple employers during the year and did not combine them during the February settlement.
- You are a freelancer or business owner.
Understanding the two main filing periods
It is common for foreigners to confuse the February and May deadlines. They are separate processes serving different purposes.
The Year-End Tax Settlement (February)
The year-end settlement is specifically for wage and salary income. Foreign workers must complete this process by the end of February for the preceding year’s earnings. This requirement applies regardless of your nationality or how long you have lived in Korea. This process determines if you overpaid your monthly withholding tax (resulting in a refund) or underpaid it (resulting in a payment).
The Comprehensive Income Tax Return (May)
If you have aggregate income—meaning your earnings come from multiple sources beyond a single salary—you must file a Comprehensive Income Tax return. The filing window is between May 1st and May 31st of the year following the income earned. For example, income earned in 2025 is reported in May 2026.
| Feature | Year-End Settlement | Comprehensive Income Tax |
|---|---|---|
| Deadline | End of February | May 1 – May 31 |
| Who Files | Wage/Salary earners | Those with aggregate income |
| Income Types | Employment income only | Business, interest, dividends, salary, etc. |
| Process | Usually via employer | Via Home Tax or Tax Office |
Which types of income must be reported?
When filing a Comprehensive Income Tax return, you must aggregate all forms of taxable income. This ensures that the progressive tax rate is applied correctly to your total earnings rather than each single source of income.
Reportable income includes, but is not limited to:
- Wage and Salary Income: Earnings from employment.
- Business Income: Income from professional services, freelancing, or owning a business.
- Interest Income: Interest earned on bank accounts or loans.
- Dividend Income: Payments received from shares in a company.
How to claim personal deductions as a foreigner?
Tax residents in Korea may be eligible for various deductions that reduce their taxable income. One notable benefit for foreign residents is the ability to claim basic personal deductions for family members.
For example, if you are a resident of Korea for tax purposes, you may claim a basic personal deduction for a spouse even if that spouse does not reside in Korea. To qualify for this, the spouse’s annual income must not exceed 1 million KRW. You must ensure you meet the specific definition of a “tax resident” to utilize these deductions.
Steps to file your annual return
If you have determined that you need to file a Comprehensive Income Tax return in May, follow these steps:
- Gather your income documents: Collect all withholding tax receipts and records of interest or dividend income.
- Verify your residency status: Confirm if you are classified as a tax resident, as this affects your eligibility for deductions.
- Choose your filing method: You can file electronically via the National Tax Service (NTS) Home Tax portal or visit your local district tax office in person.
- Submit the return: File your documents between May 1 and May 31.
- Settle the balance: Pay any remaining tax owed or provide your bank details to receive a refund.
Note: While the general deadline is May 31, some professional tax service providers may be eligible for an extension until June 30.
What happens if I miss the deadline?
Missing the May 31 deadline for Comprehensive Income Tax can result in penalties. If you have failed to file a return or have underpaid your taxes, you should contact your district tax office to file a past-due return and request a reassessment as soon as possible to minimize interest and penalties.
Frequently Asked Questions
Can I claim a deduction for my spouse if they live in my home country?
Yes, provided you are a tax resident of Korea and your spouse’s annual income is 1 million KRW or less.
I am a salaried employee; do I still need to file in May?
If your only income is the salary from your employer and you completed the February year-end settlement, you generally do not need to file in May. However, if you have other income (like a side business or significant investments), you must file.
Where can I find filing guides in English?
The National Tax Service typically releases a “Guide to Filing Global Income Tax Returns for Foreigners” in English, Chinese, and Vietnamese around late April each year on their official website.
Next Steps for Foreign Residents
To ensure you are prepared for the next tax season, we recommend the following actions:
- Create a Home Tax account: Register on the NTS Home Tax portal to manage your filings digitally.
- Keep income records: Save all records of non-salary income earned throughout the year.
- Check for April updates: Visit the NTS News section in late April to download the latest English filing guide for the current year.
Official sources
- National Tax Service: Filing returns guide
- National Tax Service: NTS English Home Page