Korean Income Tax for Foreign Workers: Rates, Flat Tax &
By WCS
If you earn a salary in South Korea on a work visa, you are part of the income tax system from your very first paycheck. Understanding how it works can save you a meaningful amount of money each year — especially because foreign workers have access to a special Korean income tax rule that locals do not. This guide walks through the progressive brackets, the optional 19% flat tax, the year-end settlement ritual every employee goes through, and the practical steps to file.
This is general information, not legal, financial, or tax advice; tax rules change and depend on your situation, so confirm current rules with the official authorities listed below before you decide anything.
How the Progressive System Works
Korea taxes residents on a progressive scale with eight national brackets, plus a local income tax surtax equal to 10% of your national tax. So the headline rates and the "real" combined rates differ. Below are the marginal national rates (figures as of the 2026 filing context; verify the latest with the National Tax Service):
| Annual taxable income (KRW) | National rate | Combined w/ 10% local surtax |
|---|---|---|
| Up to 14 million | 6% | 6.6% |
| 14M – 50M | 15% | 16.5% |
| 50M – 88M | 24% | 26.4% |
| 88M – 150M | 35% | 38.5% |
| 150M – 300M | 38% | 41.8% |
| 300M – 500M | 40% | 44.0% |
| 500M – 1B | 42% | 46.2% |
| Over 1 billion | 45% | 49.5% |
These are marginal rates: only the slice of income inside each band is taxed at that band's rate. Your taxable income is gross salary minus the employment income deduction and various personal deductions and credits, so your effective rate is usually well below the marginal figure. You can review the official framework on the National Tax Service (NTS) website.
A "resident" for tax purposes generally means someone with a domicile in Korea or who has stayed 183 days or more in a tax year. Residents are taxed on worldwide income (with treaty relief possible); short-term non-residents are taxed mainly on Korea-source income. Your residency status is a key variable, so do not assume your visa type alone decides it.
The 19% Flat Tax Option
Here is the benefit unique to foreigners. A qualifying foreign worker may elect a flat 19% national rate on Korean-source employment income instead of the progressive scale. With the 10% local surtax added, the effective rate is roughly 20.9%. Key conditions to know:
- The election generally applies for a window of up to 20 years from the first day you started working in Korea.
- Current rules tie eligibility to starting employment in Korea by a statutory deadline (reported as the end of 2026), so confirm whether your start date qualifies.
- The flat rate is applied to gross compensation with essentially no deductions or credits. You give up personal exemptions, dependent deductions, and most year-end-settlement benefits in exchange for the flat number.
Because you trade away deductions, the flat tax helps higher earners the most. As a rough rule of thumb, employees earning above roughly KRW 130 million a year often come out ahead with the flat rate, while many mid-range earners do better on the progressive scale after deductions. The smart move is to model both each year — the choice is not locked in for life and can be re-evaluated annually.
Year-End Settlement (연말정산)
Most foreign employees never file a separate annual return the way they might back home. Instead, your employer withholds tax monthly, and then a reconciliation called the year-end settlement trues everything up. Think of it as a mini tax return run through payroll, settled with your February salary.
The typical cycle:
- By mid-January (around Jan 15): consent to data sharing on Hometax so the system can pull your insurance, medical, card, and rent records into the simplified service.
- From mid-January (around Jan 17): the Simplified Year-End Settlement Service opens, auto-populating much of your deduction data.
- Late January–February: submit supporting documents to your employer (or via the one-stop service for eligible foreigners).
- With February payroll: the settlement is finalized. If too much was withheld, you get a refund — sometimes called the "13th-month pay." If too little was withheld, you pay the difference.
This applies to essentially all foreign salaried workers regardless of nationality or length of stay (daily workers are the main exception). The NTS publishes an English "Easy Guide" and runs a foreign-taxpayer helpline. You can access the system through Hometax.
How to File: A Step-by-Step Path
- Confirm your residency status and visa-based eligibility for the flat tax before the year ends.
- Run both calculations — progressive (after your realistic deductions) vs. 19% flat — using NTS tools or a tax professional. Decide which to elect.
- Give consent on Hometax by the mid-January deadline so your records flow into the simplified service.
- Gather documents the simplified service does not capture: foreign donation receipts, certain rent/housing records, dependents abroad, and private overseas insurance.
- Submit to your HR/payroll team by their internal deadline (often early-to-mid February).
- Check the result against your monthly withholding and keep the settlement statement for your records.
If you changed jobs mid-year, you generally must combine income from both employers in one settlement — ask your current HR for the prior employer's withholding receipt.
Common Mistakes to Avoid
- Defaulting to the flat tax because it sounds simple. For many mid-income earners it costs more than the progressive scale with deductions.
- Missing the mid-January consent deadline, which forces you to collect every document manually.
- Forgetting deductions the simplified service can't see, such as overseas dependents, foreign-paid items, or monthly rent receipts.
- Assuming you owe nothing back home. Some countries (notably the U.S.) tax worldwide income; treaties and foreign tax credits matter, so coordinate both systems.
FAQ
Do I have to file separately if I only have one salary? Usually no — the year-end settlement through your employer handles it. A separate May return is mainly for those with other income (business, large rental/investment income, multiple uncombined jobs).
Can I switch between flat and progressive each year? The election is generally made annually, so you can reassess as your income changes — but verify the current procedure each year.
What if I leave Korea mid-year? A settlement is typically done before departure with your final pay; ask HR to process it so you don't leave a refund or balance unresolved.
Where do I get help in English? The NTS offers English-language guides and a dedicated foreign-taxpayer helpline; major firms also offer paid expat tax services. Always cross-check anything important against the NTS directly.
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