After selling a house or land in Korea, don’t wait until next May. Income Tax Act Article 105 requires residents to file an interim capital gains return within 2 months from the end of the month of transfer. For Korean shares it’s 2 months from the end of the half-year; for the debt part of a gift with debt, 3 months from the month-end. You must file even with no gain or a loss (para. 3) and pay with the return (Art. 106). Foreign shares and derivatives are left out of interim returns. Enter the date for the deadline.
1. Property etc.: 2 months from the month-end — sold 20 October, due 31 December.
2. Korean shares: 2 months from the half-year end — second-half sales due end of February.
3. File even at a loss; pay when filing. Foreign shares and derivatives: no interim return, final return in May.
Calculator
Updates as you type. “From the end of the month, 2 months” runs to the last day of the second following month (our counting under the Civil Act, applied by Framework Act Art. 4). Weekends move to the next day; for public holidays, substitute holidays or Labour Day, move it yourself (Art. 5).
Deadlines by asset — Art. 105(1)
| Asset (Art. 94(1)) | Interim return due | Worth noting (ours) |
|---|---|---|
| Items 1 land and buildings, 2 property rights, 4 other assets, 6 trust interests | 2 months from the end of the month of transfer | Pre-sale rights count as property rights (2(a)) |
| Land in a permit zone paid before the permit | 2 months from the month-end of the permit (or zone release) | Proviso to item 1 |
| Items 3(a), (b) shares (certain listed, unlisted) | 2 months from the end of the half-year | Listed large holders: large shareholder gains |
| Debt part of a gift with debt (treated as transfer) | 3 months from the month-end | Item 3 |
| 3(c) foreign shares, 5 derivatives | No interim return | Final return next May |
Filing and paying — Art. 105(2)–(3), Art. 106
This is the “interim return”, and it applies even with no gain or a loss. With it you pay the tax computed under Article 107 less reliefs to the tax office, the Bank of Korea or a post office, deducting any occasional assessment.
Four sums — our example
| Sale (our example) | Due | Worth noting (our sum) |
|---|---|---|
| Flat, 20 October 2026 | 31 December 2026 | 2 months from 31 October |
| Flat, 10 September 2026 | 30 November 2026 | 2 months from 30 September |
| Unlisted shares, 15 March 2026 | 31 August 2026 | 2 months from 30 June |
| Gift with debt, October 2026 | 1 February 2027 | 3 months from 31 October = Sun 31 Jan → next day (Framework Act Art. 5) |
Weekend or holiday deadlines — Framework Act Arts. 4, 5
Tax periods follow the Civil Act unless a tax law says otherwise (Art. 4), and filing or payment deadlines falling on a Saturday, Sunday, a public or substitute holiday or Labour Day move to the next day (Art. 5(1)). If the national tax network is down on the last day, the deadline is the day after it’s restored (para. 3).
We counted “2 months from the month-end” under Civil Act period rules to the last day of the second following month. Period rules are in legal period calculator, the tax itself in capital gains calculator, and late penalties in tax penalty calculator.
Checklist
- ☐ Fix the transfer date
- ☐ The right deadline (month-end or half-year end)
- ☐ File even at a loss
- ☐ Pay with the return
- ☐ Two or more sales in a year? Check the final-return rule
Questions that remain
Is the transfer date the contract or completion date?
We didn’t read the timing article (Art. 98). Enter the date you’ve confirmed.
Do I file again in May?
Usually not, with exceptions; see capital gains final return.
Sources
- Korean law database (law.go.kr) — Income Tax Act Arts. 94, 105, 106, 110 — source (current text, effective 1 July 2026, Act No. 21221; checked 20 October 2026). Asset classes, three deadlines and the permit-zone proviso, foreign shares and derivatives excluded, filing at a loss, payment with the return, final return.
- Korean law database — Framework Act on National Taxes Arts. 4–5 — source (effective 2 October 2026, Act No. 21987; checked 20 October 2026). Civil Act counting; weekends, holidays, substitute holidays and Labour Day move to the next day; network outages.
- Not read. Timing of transfer (Art. 98); the Public Holidays Act list.
- What we added. The “worth noting” column and the Korean everyday gloss.
Where to check further
- NTS Hometax — filing.
- Tax office or adviser — transfer date and tax.
Written on 20 October 2026. The content is from the source; the glosses are ours.
