Expat Income Tax Korea: Flat 19% for 20 Years — When It Costs More

Under the Act on Restriction of Special Taxation, this flat-rate option for foreign workers runs for 20 years starting from the year they first worked in Korea, and it can be chosen or dropped every single year in favor of whichever rate is lower. Employees of a related company in which the employer holds 30% or more equity are excluded. Picking the flat rate means none of the Income Tax Act's tax-free allowances, deductions, reductions, or credits apply — so items that are tax-free under the regular rate, like the employer's share of health insurance premiums, become taxable income under the flat rate. You apply by filing the Foreign Worker Flat Tax Rate Application at year-end settlement, or, to have it withheld monthly, a separate application due to your employer by the 10th of the month after you worked. The pet-quarantine topic originally planned for this slot couldn't be sourced today because the Animal and Plant Quarantine Agency's website was returning a server error (503), so this topic replaced it. This was checked directly against a Nov 7, 2026 Newsis (newsis.com) report — confirm the exact forms and current requirements with National Tax Service Hometax or the foreign-taxpayer line (1588-0560).