외국인 소득세: 거주자 판정과 단일세율

1. ·A "resident" is someone with a domicile in Korea or who has stayed 183 days or more; residents are taxed on worldwide income, while non-residents are taxed only on Korea-source income.
2. ·The ordinary rates are progressive from 6% to 45% across income brackets, and a separate local income tax of 10% of the income tax applies on top.
3. ·Under Restriction of Special Taxation Act Article 18-2, a foreign employee who first starts working in Korea on or before 31 December 2026 may elect to have employment income taxed at a flat 19% (before local surtax), for income earned within 20 years of that first work date.
4. ·If you elect the flat rate, the law says the usual exemptions, deductions and tax credits do not apply, and that employment income is not aggregated into your global income tax base — so it is a clean 19% with nothing subtracted.
5. ·Your employer can withhold at 19% each month once you apply. You may compare each year and switch: the flat rate is elective, not permanent.

1. ·For the flat rate: you are a foreign employee (not a day-labourer) who first began working in Korea by 31 December 2026, and the income is within 20 years of that date.
2. ·The flat rate does not apply to work for certain related/affiliated companies (특수관계기업) as defined by decree.
3. ·For residency: 183+ days of stay, or a domicile/economic base in Korea.

1. 1Work out your residency: count your days in Korea across the tax year and check whether your home/family/economic base is here.
2. 2Estimate both scenarios: your tax at 6–45% after your realistic deductions, versus a clean 19% flat. High earners with few deductions usually win with the flat rate; most others do not.
3. 3To use the flat rate, submit the flat-rate application (단일세율적용신청서) to your employer for withholding, or apply at year-end settlement / the May return.
4. 4If you have income abroad, confirm the Korea–Vietnam tax treaty treatment to avoid double taxation, and keep foreign-tax records for the foreign tax credit.
5. 5Re-compare every year — you are not locked into either method.

National Tax Service (nts.go.kr) / Hometax (hometax.go.kr). Foreign taxpayer helpline 1588-0560 (English). Complex or business income: consult a tax accountant (세무사).

1. ·Assuming the 19% flat rate is always cheaper — for most salaries the 6–45% scale with deductions is lower.
2. ·Not realising residents are taxed on worldwide income, and forgetting to use the Korea–Vietnam treaty / foreign tax credit.
3. ·Missing the 2026 start-date condition for the flat rate — the benefit is tied to when you first began working in Korea.
4. ·Forgetting the 10% local income surtax when comparing rates.
5. ·Confusing the 3.3% freelancer withholding with final tax — it is only a prepayment; you still settle in May.