How does the year-end tax settlement (연말정산) work for foreign employees in Korea?

As a foreign employee I go through year-end tax settlement every January, and it is basically reconciling the tax withheld from your paychecks against what you actually owe, with refunds for deductions. Your employer runs it and gives you a deadline to submit documents, usually in January for the prior year. The easiest tool is the National Tax Service's Hometax simplified year-end settlement service, which auto-collects most data (medical, card spending, insurance, and rent in some cases) once you log in with a certificate. Common deductions to maximize: credit and debit card and cash-receipt spending above a threshold, national pension and health insurance, medical and education expenses, donations, and monthly rent if you qualify (you need the lease and proof of payment). Foreigners have a useful choice: you can use the normal progressive rates with deductions, or elect a flat 19 percent tax rate on gross income with no deductions, and you should compute both to see which is lower, especially if you are a high earner with few deductions. Keep your ARC, lease, and payment records, and submit whatever payroll asks for by their date.