The employer as a tax withholding agent must perform the year-end settlement of exact payroll withholding taxes for and on behalf of its employees in February of the following year after each year end as required by the IITL of Korea.
In this connection, the employer should reflect the results of year-end settlement in the February payroll of the following year accordingly. Any overpayment resulting from the year-end settlement is used to offset the payroll taxes due in February of the following year and onward until fully utilized. For any underpayment resulting from the year-end settlement, the employer should withhold additionally from the February payroll and remit it to the tax office as scheduled by March 10 of the following year (i.e., by March 10, 2024 for year 2023).
For the year-end settlement processing, the employees should gather and submit supporting documents to claim tax deductions/credits.
By the year-end settlement and filing, employees having only salary income may fulfill his/her annual individual income tax reporting obligations in Korea. On the other hand, employees having other sources of income exceeding certain thresholds than salary income are required to file additionally an annual individual income tax return (“종합소득세신고” in Korean) together with tax payment on or before May 31 of the following year (i.e., by May 31, 2024 for 2023 income).