Tax on a US stock dividend stops at the 15% withheld overseas. If the dividend lands in a Korean brokerage account, Korea adds nothing on top. Chinese stocks run the opposite way — only 10% is withheld locally, so Korea collects a further 4.4%, and Hong Kong stocks carry a 0% local rate, leaving Korea to collect the entire 15.4%.
The reference line is Korea's 14% dividend income tax rate. When the foreign rate sits below that line, Korea collects the shortfall; when it sits above, nothing more is due. The result inverts intuition: the total burden on US dividends, taxed most heavily at source, ends up lower than on Hong Kong dividends taxed at nothing.
Topping up to the 14% line
Daol Securities' overseas stock tax guide states that the base domestic rate on dividend income is 14%, that local withholding differs by country — 15% in the US, 10% in China, 0% in Hong Kong — and that Korea taxes the difference whenever the foreign rate falls below the domestic one. The Korea Council for Investor Education's tax guide describes the same mechanism: US dividends face no additional Korean withholding because of the 15% already taken, while Chinese dividends face an additional 4.4% at home.
That 4.4% is built from two pieces. The income tax shortfall of 4% (14% minus 10%), plus local income tax of 0.4%, which is 10% of that income tax. It is the same construction that turns Korea's domestic dividend rate of 14% into 15.4%. The easily missed point is that local income tax attaches only to income tax collected in Korea. Because the additional Korean withholding on US dividends is zero, the local income tax is zero too.
| Source | Local withholding (%) | Extra Korean income tax (%) | Local income tax (%) | Total burden (%) |
|---|---|---|---|---|
| United States | 15.0 | 0.0 | 0.0 | 15.0 |
| China | 10.0 | 4.0 | 0.4 | 14.4 |
| Hong Kong | 0.0 | 14.0 | 1.4 | 15.4 |
| Korean stocks | — | 14.0 | 1.4 | 15.4 |
The ordering runs against instinct. The total burden on US dividends, withheld at the highest foreign rate, is 0.4 percentage points below Hong Kong's zero-rate case. Local income tax riding only on the Korean portion produces that outcome. One cost comes attached, though: of the 15% paid to the US, the 1 percentage point above Korea's 14% line has no route back for anyone whose tax ends at withholding. The foreign tax credit only operates at the annual filing stage.
What survives on 10 million won of dividends
Here is the rate gap expressed in money. Assume 10 million won of annual dividends received through a Korean brokerage account, with total financial income at or below 20 million won so withholding settles the bill.
| Source | Dividend (10k KRW) | Paid abroad (10k KRW) | Paid in Korea (10k KRW) | Total tax (10k KRW) | Net received (10k KRW) |
|---|---|---|---|---|---|
| United States | 1,000 | 150.0 | 0.0 | 150.0 | 850.0 |
| China | 1,000 | 100.0 | 44.0 | 144.0 | 856.0 |
| Hong Kong | 1,000 | 0.0 | 154.0 | 154.0 | 846.0 |
| Korean stocks | 1,000 | — | 154.0 | 154.0 | 846.0 |
The spread between the best case (China, 8.56 million won) and the worst (Hong Kong and Korean stocks, 8.46 million won) is 100,000 won, or 1.0% of the dividend. That is the ceiling on what country selection can win you at this stage. A far larger variable waits behind it — the 20 million won financial income threshold.
How US dividends are taxed once you clear 20 million won
The Korea Council for Investor Education notes that even without additional Korean withholding, US dividends enter comprehensive taxation once annual interest and dividend income exceeds 20 million won, at which point tax paid to the US becomes eligible for the foreign tax credit. Tax that used to end at 15% withholding now joins your other income at progressive rates.
The National Tax Service rate table runs eight progressive brackets, from 6% on taxable income up to 14 million won to 45% above 1 billion. Take someone whose 30 million won of financial income is entirely US dividends, and work out the tax on the 10 million won above the threshold, bracket by bracket. The foreign tax credit is capped at the Korean tax computed on that same income, so when the 1.5 million won paid abroad exceeds the computed tax, only the computed amount is credited. Local income tax is separate.
| Taxable income bracket (10k KRW) | Base rate (%) | Tax computed on excess (10k KRW) | Foreign tax credit (10k KRW) | Additional due (10k KRW) | Effective burden on excess (%) |
|---|---|---|---|---|---|
| Up to 1,400 | 6 | 60 | 60 | 0 | 15.0 |
| 1,400–5,000 | 15 | 150 | 150 | 0 | 15.0 |
| 5,000–8,800 | 24 | 240 | 150 | 90 | 24.0 |
| 8,800–15,000 | 35 | 350 | 150 | 200 | 35.0 |
| 15,000–30,000 | 38 | 380 | 150 | 230 | 38.0 |
| 30,000–50,000 | 40 | 400 | 150 | 250 | 40.0 |
| 50,000–100,000 | 42 | 420 | 150 | 270 | 42.0 |
| Above 100,000 | 45 | 450 | 150 | 300 | 45.0 |
The last column carries the point. The effective burden resolves to max(foreign withholding rate, base rate). In brackets at or below 15%, the 1.5 million won paid to the US covers the Korean computed tax entirely and nothing more is due; the gap opens at the 24% bracket. Salaried investors usually sit above 50 million won of taxable income already, so assuming the 24% bracket or higher is the safer starting point.
The effective rate on foreign dividends converges on whichever is higher: the foreign withholding rate or your own marginal rate.
The conditions that break this arithmetic are equally clear. Deposit interest, domestic dividends, and gains on Korea-listed overseas ETFs all pull the 20 million won threshold closer, and the foreign tax credit cap moves with the share of income sourced abroad. In an account mixing domestic and foreign dividends, which income fills the excess changes the credit.
Where you opened the account decides the rest
The same US stock produces different outcomes depending on where the account sits. The Korea Council for Investor Education is blunt about it: an account opened directly with a foreign broker is subject to comprehensive taxation regardless of amount. Going through a Korean brokerage lets withholding settle anything up to 20 million won; a direct foreign account has no such line of defence.
The filing burden splits the same way. With a Korean brokerage account the tax is usually settled when the dividend arrives, and no separate return is needed. A foreign brokerage account must be reported in the May comprehensive income filing whatever the amount. For small dividend flows, the cost of that filing outweighs a 0.4 percentage point rate difference.
Tax-advantaged accounts form the other axis of the choice. How dividends work inside the domestic tax system is covered separately in the guide to Korean dividend income tax, and the 2.5 million won deduction on the capital gains side appears in the piece on US stock capital gains tax. Dividends and capital gains fall into different income categories, so their thresholds are tracked separately.
What to watch
- This year's interest and dividend total. Add domestic and foreign dividends plus deposit interest, then measure the headroom to 20 million won. That number sets your effective rate.
- Your own taxable income bracket. At a base rate of 15% or below, US dividends cost nothing extra even inside comprehensive taxation. From the 24% bracket the arithmetic changes.
- The country mix of your dividends. Dividends from jurisdictions withholding below 14% — China, Hong Kong — attract additional Korean tax. Check whether your brokerage statement itemizes the domestic portion.
- Where the account is held. Direct foreign brokerage accounts are comprehensively taxed regardless of amount, and mixing them with Korean accounts makes an aggregate filing easy to miss.
- The foreign tax credit cap. The credit is limited to Korean tax computed on foreign-sourced income. A year weighted toward domestic dividends leaves less room.
- Whether you owe a May filing. Clearing 20 million won in financial income pulls you into next May's return. Collect withholding statements and proof of foreign tax paid in advance.