Korean Semiannual Withholding Tax Payment Calculator

When an employer pays wages, it withholds income tax and passes it to the state. That is withholding, and the rule is to pay it by the 10th of the month after the month it was withheld. Small workplaces, however, can apply for approval to bundle six months of withheld tax and pay it once per half-year. This calculator decides from your headcount whether you qualify and, if so, shows the dates: when to apply, when to expect an answer, and when to pay.

The key to the ruling is the regular headcount, and it is not today's figure but the average across the twelve months of the previous year. That is why the form has twelve fields. An average of 20 or fewer qualifies, and the page also shows, month by month, how many days later the tax falls due under semiannual payment than under monthly payment.

Owners of businesses with roughly twenty staff, and whoever handles their tax. If chasing withholding tax on the 10th of every month has become a chore and you want to switch to semiannual payment but are not sure you qualify, this is where to check. Businesses that staff up for a busy season and then shrink again need to enter all twelve months, because today's headcount can be under the limit while the average is over it.

It also serves anyone who does not want to miss the application window. The window opens only twice a year, in the month before each half-year. Enter a reference date and the calculator finds the next window after it, the half-year that application covers, and the deadline by which a decision must arrive. Religious organisations qualify regardless of headcount and finance or insurance businesses are excluded regardless, so choosing the type settles those cases too.

The rule is 소득세법 제128조제1항: withheld tax is paid by the 10th of the month following the month of withholding. 제2항 of the same Article creates the exception. A withholding agent designated by Presidential Decree may, with the approval of the district tax office, pay by the 10th of the month after the last month of the half-year. That means 10 July for tax withheld in the first half and 10 January of the following year for the second half.

Eligibility is set by 소득세법 시행령 제186조제1항: a withholding agent whose regular headcount in the previous year was 20 or fewer, excluding finance and insurance, plus religious organisations regardless of headcount. 제2항 defines regular headcount as the average of the headcount at the end of each month from January to December of the previous year. The calculator adds up the months you entered, divides by the number of months, and checks whether the result is 20 or less. The statute says nothing about rounding, so none is applied. If the average is within 1 person of the threshold, the page warns that a single person could turn the ruling.

Under 제3항, applications run from the 1st to the last day of the month before the half-year you want covered: December of the previous year for the first half, June of the same year for the second. 제4항 requires the office to notify its decision by the last day of the month following the half-year in which you applied, and treats silence past that date as approval. The calculator picks the first window on or after your reference date, builds those dates, and counts the days between each month's ordinary deadline and the single semiannual payment date.

Suppose last year's month-end headcount was 16 from January to April, 18 in May, 22 in June, 24 in July and August, 22 in September, 18 in October, and 16 in November and December. The summer peak reached 24, but the twelve-month average is 18.67, which is 20 or fewer, so you may apply. Had July and August been 30 instead, the average would be 19.67. Still eligible, but only 0.33 of a person from the line: one extra person on any single month-end would have turned it.

With a reference date in mid-September, the next window is 1 to 31 December, and that application covers the first half of the following year. The decision is due by 31 January, and silence counts as approval. Tax withheld from January to June is then paid on 10 July, all on one day. January's withholding, ordinarily due 10 February, is deferred by 150 days; June's was due 10 July anyway, so it moves not at all.

The most common mistake is judging by today's staff. The statute looks at last year's twelve month-end figures, so fifteen people today means nothing if you had thirty last summer. The second is mistaking semiannual payment for a tax cut. The amount is unchanged; only the date moves. Six months of tax lands on one day, and if the withheld money has been spent on running the business, it cannot be paid.

The third is missing the deadline. The withholding late-payment penalty is 3% of the unpaid tax plus 22/100,000 of it per day, capped together at 10%, and because semiannual payment concentrates a large sum on one date, the same few days late cost far more. The fourth is assuming every kind of withheld tax is covered. Certain amounts listed in the subparagraphs of 법 제128조제2항 remain due on the 10th of the following month even with approval. Finally, a deadline that falls on a weekend or public holiday moves to the next day, but this calculator does not apply holidays, so check the calendar before you pay.