Every foreigner working or living in South Korea must deal with the Korean tax system, yet it is one of the least-explained aspects of expat life. Whether you're an E-7 salaried worker, an F-1-D digital nomad, an F-6 spouse with part-time income, or a D-2 student who did some part-time work — your Korean tax obligations depend on your residency status, income source, and whether your home country has a tax treaty with Korea. This guide covers everything you need to know.
Korean tax law distinguishes between tax residents and non-residents. A tax resident is anyone who has a domicile in Korea or has resided in Korea for 183 days or more in any tax year (January–December). Tax residents are taxed on their worldwide income — Korean-source income plus foreign-source income. Non-residents (fewer than 183 days in the year) are taxed only on Korean-source income. For most foreigners on long-term visas (E-7, F-6, F-2, H-2, etc.), you will be a tax resident from your second year in Korea and must report all income, including income from your home country.
Korea offers a special flat income tax rate of 19% (effectively 20.9% including the 10% local income surtax) for qualifying foreign workers. This is a significant benefit when Korean progressive tax rates can reach 45% for high earners. Who qualifies: foreign national employees working in Korea for a Korean employer on any work visa (E-1, E-2, E-3, E-4, E-5, E-6, E-7, etc.). The flat rate applies to Korean-source employment income only. The election is made annually — you choose each year whether to apply the flat rate or the progressive rate. The flat rate is available for 5 tax years (20 years for those in the research/engineering sector — the 5-year rule applies from the date you first received employment income in Korea). After the 5-year window closes, you are taxed at normal progressive rates. Choose the flat rate if your taxable income (after deductions) exceeds approximately KRW 88 million (the threshold where 19% beats the progressive rate after standard deductions). Below that level, the progressive rate with deductions often results in a lower bill.
If you do not elect the flat rate (or your election window has expired), Korean progressive income tax applies to your global income as a tax resident: KRW 0–14M: 6%, KRW 14M–50M: 15%, KRW 50M–88M: 24%, KRW 88M–150M: 35%, KRW 150M–300M: 38%, KRW 300M–500M: 40%, KRW 500M–1B: 42%, over KRW 1B: 45%. A 10% local income surtax applies on top of each bracket. Various deductions and credits reduce the effective rate significantly — personal deduction (KRW 1.5M per person), dependant deductions, pension insurance premiums, health insurance premiums, and credit card/cash receipt deductions are all commonly applicable.
If you are an employee with a Korean employer, your tax is withheld monthly and reconciled through 연말정산 (year-end tax settlement) in January–February of the following year. Your employer submits the settlement on your behalf. You submit your expense receipts (medical, education, insurance, credit card spending via the Hometax portal) to your employer by late January. If your withholding exceeded your actual tax liability, you receive a refund via your February payroll. If it was insufficient, you pay the difference. The Hometax portal (hometax.go.kr) has an English interface for verifying your income and deduction data. Most foreigners with a single Korean employer simply need to respond to their HR department's request for receipts in January — the employer handles the rest.
If you have multiple income sources — freelance income, rental income, investment income, or foreign income — you must file a comprehensive income tax return (종합소득세 신고) with the National Tax Service (NTS) by May 31 of the following year (covering January–December income). This applies to: F-1-D digital nomads with foreign employment income; freelancers on any visa with Korean or foreign clients; anyone with Korean investment income or rental income; E-7 workers with side income outside their main employment. Tax residents must declare global income — all sources, Korean and foreign. Foreign taxes paid are often deductible to avoid double taxation (see the tax treaty section). Use Hometax (hometax.go.kr) for electronic filing or consult a certified tax accountant (공인세무사) for complex situations.
Korea has bilateral tax treaties with over 90 countries, including the US, UK, Canada, Australia, Japan, Germany, France, and most OECD members. Tax treaties typically: ① Reduce or eliminate withholding tax on dividends, interest, and royalties ② Allow you to claim a foreign tax credit in your home country for taxes paid in Korea ③ In some cases, exempt certain categories of income from Korean tax if you are a short-term resident. For US citizens: the US-Korea tax treaty is in effect, but the US also taxes its citizens on worldwide income regardless of residency — meaning US expats in Korea often owe US taxes even after paying Korean tax. The foreign tax credit (Form 1116) reduces double taxation but may not eliminate it entirely. Consult a US-licensed CPA familiar with expat taxation for your specific situation.
In addition to income tax, most foreign workers in Korea are enrolled in the national social insurance system: National Pension (국민연금): contribution rate 9% of gross salary, split 4.5% employee and 4.5% employer. Many nationalities can receive a lump-sum refund of their contributions when they leave Korea permanently (only if their home country does not have a totalization agreement with Korea that requires contributions to be credited to their home country system — check your country's agreement). National Health Insurance (국민건강보험): contribution rate 7.09% of salary (as of 2025), split equally. Covers most medical costs with co-pays. Foreigners on long-term visas are automatically enrolled after 6 months. Long-term Care Insurance: 0.9182% (included in health premium). Employment Insurance: 0.9% employee contribution — covers unemployment benefits if you are laid off.
Elect the 19% flat rate if your annual income from Korean employment exceeds approximately KRW 88 million — run both calculations before deciding, as the break-even changes with deductions.
The 5-year flat rate clock starts from your first year of Korean employment income — track this carefully, as missing the window costs significantly in tax efficiency.
Submit your 연말정산 (year-end settlement) receipts on time in January — late submissions cannot be retroactively processed by your employer.
Use the National Tax Service's Hometax (hometax.go.kr) to check your income history, deduction eligibility, and file your own return — an English interface is available.
F-1-D digital nomads: you are a tax resident after 183 days — your foreign-source income becomes taxable in Korea. Korean tax paid is typically creditable against your home country tax liability.
If you are a US citizen: consult a dual-qualified CPA (both US and Korean) — the US-Korea tax treaty does not exempt you from US filing obligations.
When leaving Korea permanently, apply for a National Pension lump-sum refund (일시반환금) at the NPS (국민연금공단) — this is often a significant amount after several years of contributions.
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Our specialists handle korea income tax for foreigners — resident vs non-resident, flat rate, tax treaties cases regularly and know exactly what Korean immigration officers look for.
Find a SpecialistDo I need to file taxes in Korea if I only have foreign income (F-1-D)?
Yes, if you are a tax resident (183+ days in Korea). F-1-D digital nomads who live in Korea for more than 183 days in a calendar year become tax residents and must report global income — including income from their foreign employer — to the Korean National Tax Service. File a 종합소득세 return by May 31 of the following year. Korean tax paid may be creditable against your home country tax obligation under the relevant tax treaty. Many F-1-D holders work with a Korean tax accountant (공인세무사) who specialises in expat filings.
Can I get a refund on National Pension contributions when I leave Korea?
Yes, in most cases. If your home country does NOT have a totalization/social security agreement with Korea that requires your Korean pension contributions to be credited to your home pension account, you can apply for a lump-sum refund (반환일시금) of your National Pension contributions when you permanently depart Korea. Apply at any NPS (국민연금공단) office or online. You receive your total employee contributions (4.5% of each monthly salary) plus a small interest amount. Employer contributions are not refunded to you. Countries with totalization agreements (including the US, Canada, Germany, UK, Australia, and others) may require you to transfer contributions rather than take the lump sum — check the NPS website for your country.
How do I know if my home country has a tax treaty with Korea?
The Korean National Tax Service publishes the full list of Korea's tax treaties on its website (nts.go.kr) in English. You can also find treaty summaries on the OECD Tax Treaty Database. The treaty document itself specifies which income types are covered, what withholding rates apply, and whether a tax credit or exemption applies. For practical guidance on how the treaty applies to your specific situation (especially for US, UK, or Australian tax residents who may have global income filing obligations in their home country), consult a tax professional experienced in both Korean and your home country's tax law.
My Korean employer didn't withhold enough tax — what do I do?
This is addressed through the 연말정산 (year-end settlement) process in January–February. If the settlement calculation shows you owe more than was withheld, the difference is deducted from your February paycheck. This is normal and expected — it is not a penalty. If the amount owed is unexpectedly large, it may indicate that your employer was not correctly accounting for your full income (e.g., you had bonus income, multiple income sources, or the withholding table used was incorrect). You can review your withholding history on Hometax (hometax.go.kr) using your ARC number. Consult an HR specialist or tax accountant if the shortfall seems unreasonably large.