Korean-Listed vs US-Listed ETFs: Where the Tax Flips

Two ETFs can track the same S&P 500 index and still hand you different tax bills. Cross 8.33 million won of annual realized gain and the advantage switches sides: below that line the ETF listed on a foreign exchange wins, above it the Korea-listed overseas ETF does.

On rate alone, 15.4% (Korea-listed overseas ETF) beats 22% (foreign-listed ETF). But the 22% route carries an annual basic deduction of 2.5 million won, and the 15.4% route drags a tail behind it — inclusion in Korea's comprehensive financial income tax. Those two conditions flip the ranking twice.

The rate is not the difference — the income category is

The split starts with how the gain is classified, not with the rate table. According to KB's ETF tax guide, gains on Korea-listed overseas equity ETFs are treated as dividend income and withheld at 15.4%, while gains on foreign-listed ETFs count as capital gains, taxed at 22% after a 2.5 million won basic deduction. Gains on domestic equity ETFs are not taxed at all. Distributions are identical across all three: 15.4% withheld at source.

Classification matters more than the headline rate. Dividend income stacks with interest income, and once the pair clears 20 million won a year it joins your other income at progressive rates. Capital gains never enter that pool, however large. Filing duties diverge too — foreign-listed ETF gains must be self-reported between 1 and 31 May each year, and the KB guide notes a 20% penalty on unpaid tax for those who skip it.

Where the Korea-listed route starts to win

The break-even comes from one equation. With X as the annual gain, 0.154X = 0.22 × (X − 2.5m), which reduces to 0.066X = 550,000, so X = 8.33 million won. The table below works outward from that point, assuming no other financial income and no offsetting losses.

An account realizing 2.5 million won or less pays literally nothing on the foreign-listed side, and a married couple filing separate accounts gets the deduction twice. Realize 50 million won and the Korea-listed route is 2.75 million won cheaper. Stop here and the answer looks settled.

Clear 20 million won in financial income and the order reverses again

One variable is missing from that table. Because gains on Korea-listed overseas ETFs are dividend income, they stack with interest and dividends toward the 20 million won threshold. Sisa Journal e reports that crossing it pulls the excess into progressive rates reaching 49.5%, and that once the tax office flags you, your ISA account converts to a locked account — no new purchases, and the accumulated tax exemption disappears. The trap is that even an ETF paying no distribution at all still generates "dividend income" when sold.

15.4% is a floor, not a ceiling — past the 20 million won line it climbs toward 49.5%.

Take someone with 18 million won of existing interest and dividends who realizes a 10 million won gain on a Korea-listed overseas ETF. Financial income totals 28 million won, and the 8 million above the threshold is added to other income at the marginal rate. The 15.4% already withheld counts as prepaid tax, so the real extra burden is 8m × (marginal rate − 15.4%).

At the 26.4% bracket alone — taxable income between 50 and 88 million won — the Korea-listed bill runs about 1.5 times the foreign-listed one. The 8.33 million won break-even from the first table effectively vanishes for anyone who already carries financial income, and salaried investors reach that bracket first.

When you lose money: one side nets, the other does not

Loss handling splits the two routes as well. Foreign-listed ETFs let you net gains and losses across foreign stocks and ETFs for the year before applying the 2.5 million won deduction. Make 10 million on one holding and lose 8 million on another, and only 2 million is taxable — inside the deduction, so the tax is zero.

Korea-listed overseas ETFs allow no such netting. A losing ETF simply generates no tax; it does not reduce the tax on a winning one. There is a different cushion instead. As Sisa Journal e explains, the taxable amount is the lesser of the rise in the tax base price and the actual realized gain. Gains that never reach the tax base price — currency appreciation, for instance — can leave you taxed on less than you actually made.

Where the account sits matters too. The Samsung Asset Management KODEX guide notes that distributions received inside yeongeum jeochuk (private pension savings) and retirement pension accounts are tax-deferred. Those shelters cannot hold foreign-exchange listings, so inside them the choice narrows to Korea-listed products by default. How to pick among them is covered in the guide to choosing pension-account ETFs, and the mechanics of the 2.5 million won deduction appear in the piece on US stock capital gains tax.

What to watch

• This year's interest and dividend total. Add deposit interest, dividends, and Korea-listed overseas ETF gains, then measure the distance left to 20 million won. That headroom is where any decision starts.
• Unused deduction at year end. Check how much of the 2.5 million won allowance on foreign holdings remains. It does not carry over — it expires annually.
• Spreading realization across years. Concentrating sales in one year hurts under both regimes. Split across two and you get two deductions and two thresholds.
• Gap between tax base price and actual gain. Your brokerage app shows the tax base price; when its rise is smaller than your gain, the taxable amount shrinks.
• ISA lock notices. Becoming a comprehensive-tax filer freezes new ISA purchases. If you run a shelter alongside, managing the threshold outranks optimizing the rate.
• The May filing window. Foreign-listed gains are self-reported, not withheld. Miss the May after the sale year and the penalty applies.

Sources

• ETF taxes — comparing gains and distributions on domestic and foreign-listed ETFs (KB)
• ETF taxes — ETF investing basics guide (Samsung Asset Management KODEX)
• Sell a domestic ETF the wrong way and the comprehensive financial income tax bill lands (Sisa Journal e)