Monthly payroll reporting to the tax office — the monthly simplified payment statement slips again, to January 2027

The simplified payment statement, required by Article 164-3 of the Income Tax Act, tells the tax office who was paid how much. For regular employment income it is currently filed twice a year, by the last day of the month following the final month of each half-year: pay given between January and June is reported by 31 July, and pay given between July and December by 31 January of the following year. From income paid in January 2027 the cycle becomes monthly.

The rollout has been bumpy. An amendment on 31 December 2022 set the start date at 1 January 2024; a supplementary-provision amendment on 31 December 2023 moved it to 1 January 2026; and Act No. 21221, promulgated on 23 December 2025, moved it again to 1 January 2027. The National Tax Service has told employers to keep filing on the half-yearly cycle in the meantime. Nothing changes during 2026.

The penalty structure was tidied up alongside it. Failing to file by the deadline costs 0.25% of the amount paid, dropping to 0.125% if you file within one month of the deadline. If unclear or inaccurate amounts make up 5% or less of the total paid, no penalty is charged on that ground. Article 81-11(3) of the Income Tax Act then adds a temporary carve-out: for regular employment income paid between 1 January and 31 December 2027 — extended to 31 December 2028 for employers who remit withholding tax half-yearly — filing by the old deadline is enough to avoid the failure-to-file penalty. Separately, small employers with 20 or fewer regular staff in the previous year who remit withholding tax half-yearly can claim a tax credit of 200 won per income recipient from January 2027 to December 2028, capped at 3 million won a year with a floor of 10,000 won.