If you buy a Korea-listed foreign equity ETF at 9,900 won and sell it at 10,500 won, you made 600 won. But if the fund's tax base price rose only 500 won over the same period, the tax applies to 500 won, not 600. At 15.4%, that is 77 won. The example, cited by Toss Feed, contains almost everything you need to know about how these funds are taxed in Korea.
Every ETF except a domestic-equity ETF pays a 15.4% dividend income tax on trading gains. The taxable amount, though, is not your actual profit. It is the lesser of your realized gain and the increase in the fund's gwapyo gijun gagyeok (tax base price) during your holding period. Samsung Asset Management's Kodex guide states plainly that withholding applies at 15.4% to "the smaller of the rise in the tax base price and the trading gain actually realized." That is why the return shown in your brokerage account and the tax actually withheld rarely line up.
The tax base price is not the market price
Toss Feed defines the tax base price as "a price that counts only the portion of ETF returns subject to taxation," explicitly different from the price you trade at. Think of it as a second ledger tracking only the taxable slice of what the fund earns.
Why keep a second ledger? Because one fund holds both taxable and tax-exempt income. Capital gains on Korean listed stocks are tax-exempt for retail holders. Gains on foreign stocks, bond interest, dividends and derivatives income are not. The market price moves on all of it; the tax base price moves only on the taxable part. So an ETF can rise 2% on a given day while its tax base price rises 1.2%, and nothing is wrong.
The figure is published daily on the manager's website and in brokerage apps. Your broker plugs it in and withholds automatically at sale, so there is nothing to file — but if you want to know in advance what you will owe, record the tax base price on the day you buy.
The return on your screen describes your share. The tax base price describes the tax office's share. In the same fund, the two numbers move apart every single day.
Which number ends up being taxed
Assume 1,000 units bought at 10,000 won each, with a tax base price of 9,800 won that day. Working through four combinations at the point of sale:
| Case | Sale price (KRW) | Tax base price at sale (KRW) | Realized gain (KRW) | Rise in tax base (KRW) | Taxable amount (KRW) | Tax at 15.4% (KRW) | Effective rate on gain (%) |
|---|---|---|---|---|---|---|---|
| 1. Both rise | 12,000 | 11,600 | 2,000,000 | 1,800,000 | 1,800,000 | 277,200 | 13.9 |
| 2. Tax base rises more | 12,000 | 12,100 | 2,000,000 | 2,300,000 | 2,000,000 | 308,000 | 15.4 |
| 3. Price falls, tax base rises | 9,500 | 10,100 | -500,000 | 300,000 | 0 | 0 | 0 |
| 4. Price rises, tax base flat | 10,600 | 9,800 | 600,000 | 0 | 0 | 0 | 0 |
Case 1 is typical of a fund holding some Korean equities: 200,000 won of the gain came from the tax-exempt side, pulling the effective rate 1.5 percentage points below the headline 15.4%. In case 2 the rule cannot tax more than you actually made, so it stops at 15.4% — the "lesser of" test never works against the investor.
Cases 3 and 4 both produce zero tax. The first is obvious; the second looks strange, since the price rose 6%. But if all of that 6% came from tax-exempt sources, there is simply nothing to tax.
Where the same profit splits into different tax bills
The listing venue decides the regime. KB Kookmin Bank's guide notes that Korea-listed foreign ETFs pay 15.4% dividend income tax on trading gains, while ETFs listed on overseas exchanges pay 22% capital gains tax after an annual 2.5 million won deduction. The first is added to financial income; the second is taxed separately and is not.
| Item | Domestic equity ETF | Korea-listed foreign ETF | Overseas-listed ETF |
|---|---|---|---|
| Tax on trading gains | Exempt | 15.4% dividend income tax | 22% capital gains tax |
| Annual deduction (mn KRW) | n/a | None | 2.5 |
| Tax on a 3mn won gain (KRW) | 0 | 462,000 | 110,000 |
| Tax on an 8.33mn won gain (KRW) | 0 | 1,282,820 | 1,282,600 |
| Tax on a 15mn won gain (KRW) | 0 | 2,310,000 | 2,750,000 |
| Added to financial income | n/a | Yes, above 20mn won a year | No (separate taxation) |
The crossover falls out of the algebra. Setting 0.154x equal to 0.22(x - 2.5mn) gives 0.066x = 550,000, so x = 8.33 million won. Below roughly 8.3 million won of annual realized gains the Korea-listed fund is cheaper; above it the overseas-listed fund is.
One condition attaches. Gains on Korea-listed foreign ETFs join dividends and interest, and once that total passes 20 million won a year it moves into comprehensive taxation — at which point the crossover stops mattering. Overseas-listed ETFs, meanwhile, must be self-reported each May, with a 20% penalty for failing to file.
Why a losing fund does not cut your tax bill
In an ordinary brokerage account, tax on a Korea-listed foreign ETF is withheld sale by sale. A loss elsewhere in the same year does not claw any of it back. Sisa Journal e illustrates the point: make 5 million won on an ETF and lose 3 million on a stock, and you are down 3 million in principal and still owe 770,000 won in tax.
A brokerage-type ISA changes the arithmetic. Gains and losses inside the account are netted, the first 2 million won (4 million for the lower-income tier) is exempt after the three-year holding requirement, and anything above that is taxed separately at 9.9%. In the example above the taxable base falls from 5 million to 2 million won.
Overseas-listed ETFs offer a third route: capital gains are netted across the year automatically, so losses offset gains. The trade-off is that using the 2.5 million won deduction every year requires realizing gains every year, plus currency conversion costs.
What to watch
- The tax base price on your purchase date — the only input that lets you estimate the eventual withholding.
- The 8.3 million won line in annual realized gains, which decides whether a Korea-listed or overseas-listed fund costs less in tax.
- Total financial income of 20 million won, above which comprehensive taxation and health insurance premiums both kick in.
- The ISA three-year holding requirement, which is settled at maturity rather than year by year.
- The May filing deadline for overseas-listed ETFs, with a 20% penalty for non-filing.