Income tax in Korea for foreign workers: rates, the 19% flat-rate option and year-end settlement

This guide is for foreign nationals who work for a Korean employer, receive a salary taxed at source, and want to understand what Korea takes, why, and how to square up at year-end. The short answer: Korea runs an eight-bracket progressive income tax, but most foreign employees can elect a flat 19 % national rate instead — a meaningful saving at higher salaries — and every employed worker goes through a formal year-end reconciliation in January and February.

Calculator: Korea Severance Pay Calculator — work out your severance pay (toejikgeum) from your start date and last three months’ pay.

Calculator: Korea Savings Interest Calculator — see what a deposit or savings account pays after the 15.4% interest tax.

How it works

Korea taxes individuals on income earned in each calendar year (January–December). Your employer withholds income tax (원천징수, woncheong jingsu — tax deducted at source before you receive your pay) from every monthly salary payment. That withholding is an estimate. The real tax bill is calculated once a year, during yeonmal jeongsan (연말정산 — year-end tax settlement), when actual deductions and credits are applied. If too much was withheld, you get a refund via the February payslip. If too little, the shortfall is deducted.

As a foreign employee you face two distinct systems and must choose one: the standard progressive brackets — with all their deductions — or a flat 19 % national rate with no deductions at all. You cannot mix them.

Resident vs. non-resident

Your classification determines the scope of what Korea taxes. A tax resident is taxed on worldwide income — Korean earnings plus income from abroad. A non-resident is taxed only on Korean-source income. You are a tax resident if you have a domicile in Korea, or if you maintain a place of abode in Korea for 183 days or more in a calendar year. From tax years beginning 1 January 2026 onward, a new rule also treats you as a resident if you have maintained a place of abode in Korea for 183 consecutive days spanning two consecutive calendar years. Non-residents who earn Korean-source income are generally subject to withholding at flat statutory rates; they do not go through yeonmal jeongsan.

The progressive brackets

Korea’s national income tax uses eight marginal brackets. Each bracket applies only to the portion of your taxable income that falls within it — not to your entire income. An additional local income tax (지방소득세, jibang sodukse — a surcharge levied by local governments) equals 10 % of the national tax due, raising every effective rate by one-tenth.

The 19 % flat-rate option

Foreign employees and executives may elect a flat national income tax rate of 19 % on their employment income. The flat rate applies for up to 20 years from the first date of employment in Korea. To qualify, you must have started working in Korea no later than 31 December 2026 — a deadline that has been extended several times by the National Assembly and is not guaranteed to extend again. When you elect the flat rate, you forfeit every income deduction, tax exemption, and tax credit. Because deductions can be substantial for lower earners, the flat rate generally becomes advantageous only above roughly 70–80 million KRW in annual salary; below that threshold, the progressive system with deductions usually produces a lower bill. The local income tax surtax still applies on top of the 19 % national rate, making the practical combined rate approximately 20.9 %.

To apply, submit the election form to your employer at the time of monthly withholding or yeonmal jeongsan, or file directly with the National Tax Service (국세청, NTS) at annual return time.

Year-end settlement (yeonmal jeongsan)

Every January your employer runs the reconciliation for the prior tax year. You submit deduction evidence — receipts, insurance certificates, medical records — by mid-January. Your employer then recalculates your annual tax liability using the actual figures, compares it to the total withheld across the year, and pays or collects the difference through the February salary. Foreign residents who were in Korea for 183 days or more in the year go through exactly the same process as Korean employees. The NTS operates a simplified Hometax service (홈택스 간소화, Hometax gansohwa — a portal where institutions pre-load your spending data) that reduces the paperwork burden. Foreigners must register with this service or ask their employer to do so on their behalf by mid-January each year.

Tax treaties

Korea has income tax treaties with 97 countries (as of January 2026, per NTS records). A treaty can reduce or eliminate double taxation. In practice, this matters most for non-residents earning Korean-source income subject to withholding, and for residents who also have foreign-source income taxed abroad. To claim a reduced treaty rate, the foreign taxpayer must supply the withholding agent (usually the Korean employer or payer) with a certificate of tax residency issued by the home-country tax authority, and in some cases a beneficial-ownership declaration. Claims must be made before or at the time of payment; retroactive claims can be complex.

Why Korea does it this way

Korea introduced the flat-rate option for foreign workers in 2002 as part of a broader effort to attract skilled overseas talent and multinational investment. Progressive rates with numerous deductions work well for long-term Korean residents who accumulate qualifying credits over time — housing savings, dependants, pension contributions — but newly arrived foreigners often lack those credits and find the administrative burden high. The flat rate offered a simple alternative. The 20-year window and the December 2026 start-date ceiling were added and periodically extended by the National Assembly to keep the incentive time-limited and revenue-neutral over the long run. The yeonmal jeongsan system itself dates to the 1970s and reflects Korea’s preference for employer-mediated tax administration: the state collects most data through businesses rather than relying on individual self-reporting.

The numbers that matter

Source: National Tax Service / PwC Tax Summaries, brackets as of tax year 2025. The local income tax is 10 % of the national tax amount, not 10 % of income.

What it means for you

If you earn above roughly 70–80 million KRW annually, run a comparison between the 19 % flat rate and the progressive system. The flat rate is simpler and likely cheaper at higher salaries, but you lose all deductions. Ask your employer’s payroll team or a registered Korean tax agent (세무사, semusa) to model both scenarios with your actual figures before electing.

If you earn below that threshold, the progressive system with deductions is likely cheaper. Collect evidence of qualifying expenses throughout the year: credit and debit card receipts (pre-loaded into Hometax), medical bills, insurance premium certificates, and dependent-related documents.

For the yeonmal jeongsan process, do the following each January: confirm with your employer whether they use the NTS Hometax simplified service; if yes, register on Hometax (hometax.go.kr) and consent to sharing your data; if no, download your spending data from Hometax yourself and submit the printouts to HR. Check your February payslip — the refund or additional deduction will appear there.

If your home country has a tax treaty with Korea, keep a current certificate of tax residency from your home-country tax authority. Present it to your Korean employer before income is paid so the correct treaty rate can be applied at source. Retroactive corrections are possible but administratively burdensome.

For documents an employer needs from a foreign employee: a copy of the alien registration card (외국인등록증, waegukin deungnokjeung) or passport; the flat-rate election form if the employee is choosing 19 %; a certificate of tax residency from the home country if a treaty rate applies; and during yeonmal jeongsan, the income deduction evidence package (or confirmation that the employee has consented to Hometax data sharing).

FAQ

Can I switch between the flat rate and the progressive system each year?

Yes. The election is made annually — either at the monthly withholding stage or during yeonmal jeongsan. You are not locked in permanently. However, you cannot combine them in a single year: once you elect the flat rate for a tax year, all deductions and credits are forfeited for that year.

What happens to my taxes if I leave Korea part-way through the year?

If you leave permanently mid-year, your employer should run a departure settlement (출국 정산, chulguk jeongsan) at the time you leave. This closes your tax account for the portion of the year you worked. If you have additional Korean-source income after departing — such as a severance payout — that income is subject to withholding as a non-resident. Consult the NTS or a semusa before your departure date.

Do I still need to file a tax return in Korea if my employer does yeonmal jeongsan?

For most salaried foreign employees, yeonmal jeongsan replaces the need to file a separate annual return. However, if you have additional Korean-source income beyond your salary — freelance fees, rental income, interest, or capital gains — you may need to file a comprehensive income tax return (종합소득세 신고, jonghap sodukse singo) with the NTS each May for the prior year. The NTS publishes English-language guidance on its website (nts.go.kr) and operates a call centre with multilingual support.

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