SEISEI INSIGHTS — Family Wealth
Worldwide Taxation and Residency Status: The First Question for Foreign Wealth Holders in Japan
2026-06-13
You have lived in Japan for over a decade, earn tens of millions of yen a year, and still hold two properties and a brokerage account back home. "I file Japanese taxes on my Japanese income — my home-country assets have nothing to do with Japan." We hear this from foreign residents constantly, and in most cases it is wrong. Article 7, Paragraph 1, Item 1 of Japan's Income Tax Act subjects residents other than non-permanent residents to taxation on all income. Rental income from your home country and gains on your overseas shares are, in principle, taxable in Japan.
"Domicile" in Tax Law Is Not Your Resident Registration
Everything starts with where you live — in the tax-law sense. "Domicile" under the Income Tax Act is interpreted not as the address on your resident card, but as the "base of one's life" under Article 22 of the Civil Code: where you work, where your family lives, where the center of your life actually is. Substance, not form.
Three Residency Categories, Three Scopes of Taxation
| Category | Definition | Scope of taxation |
|---|---|---|
| Non-resident | Base of life outside Japan | Japan-source income only |
| Non-permanent resident | A resident without Japanese nationality whose periods of residence in Japan total 5 years or less within the past 10 years (Income Tax Act, Art. 2(1)(iv)) | Income other than foreign-source income, plus foreign-source income remitted to Japan |
| Permanent resident (residents other than non-permanent residents) | All other residents | Worldwide income (Income Tax Act, Art. 7(1)(i)) |
Note the number: five years, not ten. Worldwide taxation begins once your cumulative residence exceeds 5 years within any 10-year window — most long-term foreign residents crossed that line long ago.
The Tax Authority Already Knows: CRS and the Overseas Assets Report
Worldwide taxation does not rely on voluntary disclosure. Under the Common Reporting Standard (CRS), Japan automatically exchanges financial account information with numerous jurisdictions — with China, since 2018. Your overseas account balances and interest income reach Japan's National Tax Agency without any action on your part.
In addition, residents (excluding non-permanent residents) holding overseas assets exceeding ¥50 million in aggregate as of December 31 must file an Overseas Assets Report with the tax office (Act on Submission of Reports concerning Overseas Wire Transfers, Art. 5). Failure to file without justifiable grounds, or false statements, carries imprisonment of up to one year or a fine of up to ¥500,000 (Art. 10), and under-reporting penalties are increased by 5% for unreported assets.
Relief from Double Taxation Is Reserved for Those Who File Correctly
Where income already taxed in your home country is taxed again in Japan, relief mechanisms exist: the foreign tax credit (Income Tax Act, Art. 95) and tax treaties, including the Japan–China treaty. The critical point: these reliefs presuppose proper filing in both countries. If you never filed at all, you lose the credit — and face simultaneous scrutiny from two tax authorities.
Treat It as a Structural Question
In our experience, most problems arise not from concealment but from not knowing an obligation already existed. Three things to confirm:
- Are you a permanent or non-permanent resident? The scope of taxation differs fundamentally.
- What is the aggregate value of your overseas assets? This determines the reporting obligation.
- Have you paid tax in your home country? This determines whether the foreign tax credit applies.
Mapping residency status, asset locations, and filing positions in both countries onto a single structural diagram is the starting point of cross-border tax architecture.
This article provides general information on tax systems and does not constitute individual tax consultation. Specific filings and tax computations are handled by licensed partner tax accountants whom we introduce.