Korea withholds capital gains tax on non-resident stock sales at the point of sale
Holding a Korean stock for more than a year does nothing to lower a non-resident's capital gains tax. Investors used to US-style long-term discounts often assume otherwise, and they're wrong. So what actually determines the tax bill? One number: KRW 5 billion in single-stock holdings as of December 31. Cross that line and you move from an 11%-or-22% withholding calculation into a 22% to 27.5% major shareholder bracket, without buying a single new share. Here's how that threshold works, why the holding period is a red herring, how treaties can override both rates, and what the gap actually looks like between a small retail seller and someone sitting on a large concentrated position.
- Roughly 11% of gross sale proceeds is one option for the withholding calculation, applied regardless of profit or loss.
- 22% of the net capital gain is the alternative, applied only to the actual profit.
- Korea withholds whichever of the two is lower. That's confirmed in the Korean tax code and in Chambers Practice Guides for 2026.
- Tax treaties between Korea and the investor's home country can override both rates entirely, sometimes down to a full exemption.
- Listed and unlisted shares get treated differently. Unlisted non-SME shares carry a domestic 22% capital gains tax that doesn't directly apply to the non-resident withholding rule, but it shapes the broader landscape and is worth knowing about.
Confirm which of the two rates applies to your specific sale before assuming the standard 22% net-gain figure applies. Holding period, gain size, and residency status all interact with this dual-rate structure differently, and that holding-period point deserves a closer look since it's the most common source of confusion.
A one-year holding period does not by itself lower the tax rate for non-residents
A lot of investors assume that holding a Korean stock past the one-year mark automatically unlocks a preferential long-term rate, the way it works in the US. It doesn't. For non-resident individuals selling listed shares, Korea's withholding rule builds in no separate long-term discount. What actually changes the outcome is whether you qualify as a major shareholder, not how long you've held the position.
- Major shareholder threshold: hold stock in a single company worth KRW 5 billion or more as of December 31, and you lose the retail exemption entirely.
- Major shareholders face a 22% to 27.5% tax bracket range on gains, depending on whether the capital gain is KRW 300 million or less, or exceeds that amount.
- A higher flat rate applies if a major shareholder sold non-SME shares held for less than one year. That's a penalty aimed at short holding periods, not a reward for long ones, and the distinction trips people up constantly.
- Retail-level non-residents below the KRW 5 billion threshold fall under the standard 11%-of-proceeds or 22%-of-gain rule described above. The one-year mark plays no independent role for them at all.
Check your aggregate holding value in a single Korean company at year-end, not your holding period, when estimating exposure to the major shareholder rates. Even this threshold-based calculation can get overridden entirely by treaty terms, which is the next thing worth checking.
Tax treaties frequently eliminate the withholding tax altogether for foreign sellers
Korea has signed tax treaties with dozens of countries, and many of them hand taxing rights over capital gains from portfolio investment exclusively to the investor's home country, not to Korea. An investor from a treaty country can often apply for a reduced rate or full exemption on the sale of KOSPI or KOSDAQ shares, as long as the paperwork gets filed with the brokerage or custodian in advance.
- Check for a treaty exemption first, before assuming the 11% or 22% withholding applies. Chambers confirms capital gains are either exempt under an applicable tax treaty or subject to withholding tax, and there's no middle ground.
- Residency status under Korean tax law determines eligibility. Non-residents (short-term visitors, anyone without sufficient physical presence in Korea) face the mandatory withholding unless a treaty overrides it.
- Documentation typically means a certificate of residency from the investor's home tax authority, submitted to the withholding agent before the sale settles.
- The process runs through the brokerage, not the investor directly. The withholding agent handles calculation, deduction, and remittance, so you rarely file anything with Korean tax authorities yourself.
If you're trading through a global custodian or international brokerage platform, confirm in advance whether treaty benefits get applied automatically or whether you need to file a separate claim. Miss that filing and you could end up paying the full withholding rate for nothing. With the rate rules and treaty overrides both on the table, the real question is how they combine, and that depends heavily on the size of the holding.
Tax bills differ sharply between small retail sellers and large single-stock holders
The gap between a small non-resident retail investor and someone approaching the KRW 5 billion major shareholder line is enormous in practical terms. Where your portfolio sits on that spectrum determines the entire tax outcome. Worth noting too: the financial investment income tax that would have restructured these rules for 2025 got formally withdrawn, so the standard capital gains framework described here still governs.
- A small non-resident retail seller faces the lesser of 11% of gross proceeds or 22% of net gain, unless a treaty exemption applies. No major shareholder complications enter the picture.
- A large single-stock holder near KRW 5 billion risks crossing into the 22%-27.5% major shareholder bracket simply because of year-end market value, even without adding a single new share.
- Unlisted SME shares carry an 11% capital gains tax rate inclusive of local income tax, notably lower than the 22% rate that applies to unlisted non-SME shares.
- A KRW 2.5 million basic deduction applies annually under the general capital gains framework, though it interacts differently with non-resident withholding than it does with resident filings.
- And capital losses only offset gains within the same category and year. They can't be carried forward. Korea's rules give you no flexibility there, so plan accordingly.
Before executing a large sale near year-end, anyone holding a concentrated position should run the December 31 market value against the KRW 5 billion threshold. Crossing it turns a modest withholding rate into a significantly higher bracket calculation, and the holding period never enters into that math at all. The KRW 5 billion year-end market value does, and it remains the one number that decides whether a non-resident seller pays a modest withholding rate or a major shareholder bracket rate on the exact same sale.