Korea's new ISA doubles the ceiling and shuts US index funds out of it

In the tax revision unveiled on August 3, the Korean government created a new account called the productive finance ISA. Tax on interest and dividends inside it disappears and the lifetime ceiling doubles from the existing ISA, but the only things it may hold are domestic assets.

South Korea plans tax breaks to revive economic growth (UPI, 2026-08-03)

출처: upi.com

An ISA is a tax favoured account that holds deposits, stocks and funds together and trims the tax on what they earn. The existing Korean ISA exempts only the first 2 million won of gains and takes 9.9 percent of the rest separately, while the new account leaves interest and dividends untaxed with no ceiling at all. Young savers get one more thing. Anyone aged 15 to 34 with total salary of 75 million won or less can deduct 10 percent of the year's contributions from income. Paying in comes back as a deduction at year end settlement. The annual contribution limit is 20 million won, and the account runs in three year contracts up to ten years in total.

Looking only at the size of the bowl

What it is allowed to hold

The new account is limited to domestic assets: Korean stocks, domestic equity funds, and vehicles such as the National Growth Fund. Exchange traded funds that track US indexes drop out even when they are listed in Seoul. The target of that clause is not hard to see. Korean retail investors held $161.1 billion of overseas stocks as of the end of September 2025, and the retail share of the country's outbound equity investment, less than one in ten before 2020, is now more than one in three. The idea is to turn the flow that had been filling tax favoured accounts with US index funds back toward the domestic market.

Korea offers tax breaks to curb overseas stock outflows (Korea Herald, 2025-12-24)

출처: koreaherald.com

Holding domestic assets only also means that when one country's market shakes, there is nothing inside the account to share the shock. The saver takes the tax break and gives up the spread.

What the 9.73 million existing accounts lose

The same revision reaches back into accounts that are already open. At the end of June there were 9.73 million existing ISAs holding 73 trillion won. First, unused contribution room can no longer be carried into the next year. A saver who put in 5 million won this year could until now add the missing 15 million on top of the following year's room. The habit of catching up in a year when the bonus lands is closed off. Second, a contract that could effectively be rolled forward indefinitely is now capped at five years. The force of a tax favoured account comes from untaxed principal going straight back to work, and closing the account every five years shortens that runway.

What splits the two readings of the same bill is whether you look at the size of the account or at the range of assets it is allowed to hold.

Where the productive finance ISA meets the December Assembly

What exists today is a government proposal, and tax bills are normally settled in the regular National Assembly session in December. Before deciding how to use the account, the thing to watch is not the size of the benefit but whether the domestic assets only clause survives intact. If it passes as written, the practical answer is to run a tax favoured account for domestic assets next to an ordinary account for overseas indexes; if the Assembly opens the door to foreign assets, one account does the job. Anyone already holding an ISA also has reason to weigh that this year is the last one with carryover in it.