Foreign employees in Korea may be able to choose a 19% flat income tax, or 20.9% including local income tax, instead of Korea’s normal progressive income tax rates. The catch is that the flat tax applies to gross employment income and gives up most deductions and credits. For many ordinary salaries, progressive tax is cheaper; the flat tax usually becomes interesting only for higher earners. Run the numbers before choosing it.
Korea gives many foreign employees a tax choice that local employees usually do not have: use the normal progressive tax system, or elect a flat 19% tax rate on employment income.
At first, 19% sounds simple and attractive. But it is not automatically cheaper. The flat-tax route removes the deduction system that makes Korea’s normal tax calculation much softer than the headline brackets suggest.
What is Korea’s 19% flat tax?
The flat tax is a special option for eligible foreign employees.
Instead of using Korea’s progressive income tax rates, you apply a flat 19% national income tax to employment income. With local income tax added, the total rate is effectively 20.9%.
This can be useful if your salary is high enough that Korea’s progressive system would tax your top income at much higher rates.
What do you give up?
The flat tax is simple, but the tradeoff is big.
If you choose it, you generally give up deductions and credits that may apply under the normal system, such as:
earned-income deductions
personal deductions
insurance-related deductions
tax credits
other year-end settlement benefits
That is why the flat tax can be worse for normal salaries. A worker earning around ₩50M–₩80M may pay much less under the progressive system after deductions.
Who actually benefits?
Usually, higher earners.
There is no universal cutoff because the answer depends on salary, family situation, deductions, residence status and payroll details. But as a rough rule, the flat tax is usually worth checking once salary moves into the ₩150M–₩200M+ range.
Typical people who may benefit include:
executives
senior engineers
finance professionals
expat-package employees
highly paid specialists
For average salaries, do not assume the flat tax is a perk. It may simply make your tax bill higher.
How do you elect the flat tax?
Tell your company’s payroll or HR team that you want to check the foreign-worker flat tax option.
In practice, it can be handled through payroll withholding or during year-end tax settlement. Your employer or tax preparer may ask for a form or supporting details.
You can reassess by year. If your salary rises sharply, or your deductions change, run the comparison again before the next tax year.
Salary Calculator for Foreigners
Salary Calculator for Foreigners — Enter your Korean salary and compare flat tax vs progressive tax before choosing.
Use it before signing an offer, negotiating compensation or asking payroll to apply the flat rate.
One more thing: National Pension refund
Tax is not the only money issue foreign workers should check.
Depending on your nationality and Korea’s pension rules with your country, you may be able to claim a National Pension lump-sum refund when you permanently leave Korea.
For some workers, the pension refund matters more than small tax optimization. Check it before leaving Korea, not after.
Frequently asked questions
Is Korea’s flat tax really 19%?
The national income tax rate is 19%. With local income tax included, the effective total is usually 20.9%.
Is the 19% flat tax always cheaper?
No. For many normal salaries, Korea’s progressive tax system is cheaper after deductions and credits.
Who should consider the flat tax?
High earners should check it first, especially around ₩150M–₩200M+ annual salary. Below that, progressive tax often wins.
Can I change later?
In many cases, the choice can be reviewed by tax year. Ask payroll or a tax professional before year-end settlement.
Is this tax advice?
No. This is general information for foreign workers in Korea. Confirm your exact case with your employer, a tax professional or the National Tax Service.