Cross-Border
Dual Citizen (Korea-US) Inheritance: Tax Rules Explained
In Brief
Korea-US dual citizens are taxed by both systems, but how depends on residency (Korean side) and domicile (US side) — not citizenship. The most common mistake: assuming the Korean passport guarantees resident-rate deductions. It does not. 183 days in Korea per year is the bright line.
Two Systems, Two Different Tests
| System | What matters | What does NOT matter |
|---|---|---|
| Korean inheritance tax | Decedent's residency (address + 183 days) | Citizenship |
| US estate tax | Decedent's citizenship (or domicile if non-citizen) | Where assets are located |
A Korea-US dual citizen who lives full-time in Korea: Korean resident (full deductions) + US citizen (worldwide estate tax over $15M exemption, 2026).
A Korea-US dual citizen who lives full-time in the US: Korean non-resident (₩200M deduction only) + US citizen (same worldwide estate tax).
The "Korean Passport ≠ Korean Resident" Trap
Many dual citizens (or families of dual citizens) assume that holding a Korean passport entitles them to resident-rate Korean inheritance tax deductions. It does not. If the decedent had been living in Los Angeles for 30 years with only annual visits to Korea, they are a Korean non-resident — and the heirs lose ₩500M lump-sum + ₩3B spousal deduction.
The financial difference on a ₩2.5B Korean estate is roughly ₩440M ($310K) more tax. See our non-resident penalty guide.
The Three Planning Moves Most Dual Citizens Miss
1. Re-establish Korean residency before death
If the decedent has time (good health, advanced age) and significant Korean assets, returning to Korea for 183+ days per year for several years before death can restore resident-rate deductions. This is the single highest-ROI move in Korean estate planning for dual citizens.
2. 10-year gifting plan
Gifts to lineal descendants more than 10 years before death are excluded from the inheritance tax base. Korean annual gift exclusion is ₩50M per adult child. A 70-year-old parent gifting now can move ₩500M+ off the estate over 10 years.
3. US estate tax exemption ($15M in 2026)
If the dual-citizen decedent's worldwide estate (Korean + US) is under $15M (2026 federal exemption), no US estate tax applies — but Form 706 may still need to be filed. Korean tax paid is creditable via Form 706-CE (no Korea-US estate tax treaty but unilateral relief under IRC §2014).
Renunciation Question
Some dual citizens consider giving up US citizenship to escape worldwide US estate tax. The exit tax (IRC §877A) treats this as a deemed sale of all assets — often more expensive than the estate tax it avoids. Get a US-licensed expat tax specialist before going down this road.
Korean Side vs. US Side — Who We Handle
We handle the Korean side directly: residency determination, Korean inheritance tax filing, asset valuation, deductions, Korean court filings. The US side (Form 706, exit tax planning, expatriation analysis) is referred to partner US-licensed attorneys and CPAs.
General information only — not tax or legal advice. The operator is not a US-licensed attorney or CPA. US-side estate tax, expatriation, and exit tax are referred to partner US professionals.