The income deduction on Korea's citizen-participation National Growth Fund (gukmin seongjang pendeu) stops at a contribution of 70 million won. The deduction rate is split into brackets by investment amount — 40%, 20%, then 10% — and filling all three yields exactly 18 million won of deduction. Nothing above that adds a single won. According to Korea.kr, the second tranche goes on sale from September 30 to October 15, a two-week window, with 600 billion won available first-come, first-served through 10 banks and 14 securities firms. The per-person contribution cap is 200 million won — but for deduction purposes, only the first third or so matters.
That does not mean the rest is wasted. The reduced dividend tax rate applies to the full contribution cap for up to five years. But that benefit only materializes if distributions actually arrive, whereas the deduction is locked in the moment you contribute. Two benefits of different natures, operating in different ranges of the same product — that is what makes the arithmetic here confusing.
The 40% bracket is about the amount invested, not your income
This is where most readers go wrong. Reading "40% up to 30 million won" as the rate for people earning under 30 million throws off every subsequent number. The tax-law amendment reported by Korea Taxation Times makes clear these are investment-amount brackets. Whatever your income, the first 30 million won is deducted at 40%, the 30–50 million slice at 20%, the 50–70 million slice at 10%, and past 70 million the deduction freezes at 18 million won.
Stack the brackets and the cap explains itself: 30 million × 40% = 12 million, plus 20 million × 20% = 4 million, plus 20 million × 10% = 2 million. Total: 18 million. The ceiling was not set separately — it is what falls out of filling every bracket.
| Contribution | Bracket math | Cumulative deduction (KRW 10k) | Effective rate on contribution (%) |
|---|---|---|---|
| 10M won | 10M × 40% | 400 | 40.0 |
| 30M won | 30M × 40% | 1,200 | 40.0 |
| 50M won | + 20M × 20% | 1,600 | 32.0 |
| 70M won | + 20M × 10% | 1,800 | 25.7 |
| 100M won | no further deduction | 1,800 | 18.0 |
| 200M won (cap) | no further deduction | 1,800 | 9.0 |
The last column tells the story. The rate holds at 40% up to 30 million won, drops to 25.7% at 70 million, and falls to 9.0% if you fill the 200 million cap. Measured by deduction alone, every additional won is less efficient than the one before it.
What actually comes back at your marginal rate
An income deduction shrinks your taxable base, not your tax bill directly. The cash back equals the deduction times your marginal rate. Korea's brackets run 6% up to 14 million won of taxable income, 15% from 14 to 50 million, and 24% from 50 to 88 million; add the 10% local income surtax and the real rates are 6.6%, 16.5%, and 26.4%. The same 18 million won deduction is worth 1.19 million won to one taxpayer and 4.75 million to another.
| Contribution | Deduction (KRW 10k) | At 6.6% (KRW 10k) | At 16.5% (KRW 10k) | At 26.4% (KRW 10k) |
|---|---|---|---|---|
| 30M won | 1,200 | 79 | 198 | 317 |
| 50M won | 1,600 | 106 | 264 | 422 |
| 70M won | 1,800 | 119 | 297 | 475 |
| 200M won | 1,800 | 119 | 297 | 475 |
Note that the last two rows are identical. In deduction terms, 70 million won and 200 million won are worth exactly the same. The 130 million difference is money committed purely for the dividend tax break.
Two caveats. First, if the 18 million deduction pushes your taxable base into a lower bracket, the saving is smaller than the table suggests — someone with a base of 52 million lands at 34 million after the deduction, so only part of it escapes the 24% band. Second, Korea Taxation Times notes an annual aggregate deduction ceiling of 25 million won across all such items. If you already claim venture-investment deductions, check whether there is room left for the full 18 million.
The 40% rate is not a break for lower earners. It is a break on the first 30 million won, and only that.
Why you see both 9% and 9.9%
Coverage cites the separate-taxation rate as 9% in some places and 9.9% in others. Both are right. The statute sets the income tax rate at 9%; the local income surtax, 10% of that, adds 0.9%, so withholding lands at 9.9%. It mirrors ordinary dividend income, where the 14% statutory rate is quoted as 15.4% once the surtax is included.
So the saving on distributions is 15.4% minus 9.9%, or 5.5 percentage points. Since no yield is promised, the won amount cannot be calculated in advance — but the 5.5-point spread is fixed. There is a secondary effect too: income finalized under separate taxation is excluded from the aggregate financial-income tax, so for anyone whose interest and dividends already approach the 20 million won annual threshold, avoiding aggregation can matter more than the rate itself. The same statutory pattern appears in the 9% separate taxation on REIT dividends, where caps, holding periods, and eligibility are structured much the same way.
Keep the size figures distinct. The per-person contribution cap is 200 million won, while Safetimes reports the second tranche is built from 600 billion won of public subscription plus 120 billion won of subordinated government capital, for 720 billion total. Subordinated capital absorbs losses first — but loss cushioning is not principal protection. The fund invests in companies across 12 strategic industries including semiconductors, batteries, bio, AI, and defense, so the net asset value moves.
What changed in the second tranche
Financial News reports the first tranche sold out its 600 billion won in five business days, drawing roughly 30,000 subscribers. The second keeps the size at 600 billion but raises the allocation reserved for lower earners to 50% of sales, or 300 billion won, up from 20% the first time. "Lower earner" here means employment income of 50 million won or less — or, where other income exists, comprehensive income of 38 million or less. If the reserved tranche is not exhausted in week one, week two sells without distinction.
Eligibility runs to anyone 19 or older, or 15 and older with employment income, and the tax treatment requires a dedicated account holding only this fund. First-tranche subscribers cannot join the second. The term is five years with no early redemption, and transferring within three years triggers clawback of the tax benefit. Because the locked-up period is paired with the deduction, treating the 40% bracket as a short-term play does not work.
What to watch
- Your marginal rate — at a taxable base under 14 million won, an 18 million deduction is worth 1.19 million. Measure the gap between "40% deduction" and cash returned
- The 25 million won annual aggregate deduction ceiling — check what other items already occupy it
- Your contribution bracket — anything above 70 million won earns zero deduction. Is the 5.5-point dividend saving the only reason it is there?
- Five-year term, three-year clawback — whether the no-redemption condition collides with your cash needs
- Sell-out pace — the first tranche closed in five business days. Watch how the 50% reserved allocation changes week-one demand
- Net asset value — subordinated government capital does not stop the valuation from moving with the underlying industries
The conditions under which this arithmetic breaks are equally clear. Bracket rates and caps sit in the special tax law and can be amended, and the special treatment is set to expire in 2030. Minimum subscription amounts are left to each distributor, anywhere from zero to one million won, so one number still has to be confirmed at the counter. For the difference between a deduction and a tax credit, the pension-savings and IRP tax credit math makes the contrast plain.
Sources
- Second tranche of National Growth Fund on sale for two weeks from the 30th (Korea.kr)
- National Growth Fund second tranche opens September 30 (Financial News)
- Special tax law granting up to 18 million won deduction passes the National Assembly (Korea Taxation Times)
- Second National Growth Fund launches on the 30th with 9.9% separate taxation on dividends (Safetimes)