US tax filing for Americans in Japan

The baseline obligations

If you're a US citizen or green-card holder living in Japan, you file a US federal return (Form 1040) every year, reporting all worldwide income. Your Japanese employer's gensen-chōshū-hyō (year-end tax withholding statement) translates into US-tax terms as wages on Form 1040 Line 1; Japanese national and local income tax become Foreign Tax Credit on Form 1116, or your wages may be excluded under the Foreign Earned Income Exclusion (Form 2555), whichever produces the better US result.

If your total foreign financial accounts exceed $10,000 at any point during the year, you also file FBAR (FinCEN Form 114). If you meet higher thresholds, you additionally attach Form 8938 (FATCA) to the 1040.

Things that trip up American taxpayers in Japan specifically

PFIC: the Japanese mutual fund trap

Most Japanese mutual funds, ETFs, and investment trusts qualify as Passive Foreign Investment Companies (PFICs) under US tax law. PFIC treatment is harsh: it taxes all gains as ordinary income regardless of holding period, disallows preferential long-term capital gains rates, and requires Form 8621 for each PFIC held.

This catches a lot of Americans in Japan who open a tokutei kōza (specified account) at a Japanese broker and buy Japanese mutual funds or NISA-eligible funds. That's a normal thing to do as a Japan resident, and a potentially expensive thing to do as a US taxpayer. Americans abroad are generally better off holding US domiciled ETFs (VTI, VXUS) through a US brokerage that accepts overseas addresses (Charles Schwab International, Interactive Brokers) rather than buying Japanese funds.

Kōsei nenkin and the US-Japan Social Security Totalization Agreement

Contributions to Japan's kōsei nenkin (welfare pension) are generally not excluded from US wages; they sit in your US taxable income. On the other side, the US-Japan Totalization Agreement prevents you from being required to pay both US Social Security and Japanese kōsei nenkin on the same wages.

If you're self-employed in Japan (kojin jigyōnushi), the Totalization Agreement typically assigns your social security obligation to Japan, which means you're exempt from US self-employment tax, but only if you obtain a Certificate of Coverage from the Japan Pension Service. Without that certificate, the IRS default is that you owe US self-employment tax on your Japanese self-employment income. Getting the certificate in advance is cheap and saves a material amount of money.

K.K. and GK ownership: Form 5471 and GILTI

If you're a Japan-based business owner with a K.K. (kabushiki kaisha) or GK (gōdō kaisha) that you own 10% or more of (common for consultants who incorporate locally), you generally owe Form 5471 annually. Form 5471 is one of the heaviest filings in the code, and failure to file carries a $10,000 per-year penalty that applies even if there's no US tax due.

For controlled foreign corporations (over 50% US-owner ownership), GILTI (Global Intangible Low-Taxed Income) rules may impose US tax on the corporation's earnings even if nothing is distributed to you. The planning moves around GILTI (Section 962 elections, GILTI high-tax exclusion) are technical and generally require a specialist who's seen the Japan fact pattern before.

The US-Japan tax treaty: useful but narrow

The US-Japan treaty resolves some double-taxation issues but is narrower than many Americans assume. Key provisions Americans in Japan use most:

• Article 17 (Pensions). Pensions from Japanese sources paid to US residents are generally taxed only by Japan, with some carve-outs for government pensions.
• Article 23 (Elimination of Double Taxation). Authorizes the US Foreign Tax Credit mechanism that eliminates most double taxation on wages.
• Savings clause. The treaty's most important limitation: it preserves the US's right to tax its citizens regardless of the treaty, so most treaty benefits don't apply to US citizens. This is the reason the treaty is less protective for citizens than residency-based expats assume.

Rental property in Japan

If you own an apartment in Tokyo or a house in the Kanto countryside and rent it out, the rental income appears on Schedule E of your 1040, with Japanese income tax paid on the property available as a Foreign Tax Credit. Depreciation is computed in JPY and converted to USD at the yearly average exchange rate. Japanese property depreciation timelines (22 years for wooden residential) differ from US ones (27.5 years); the US rules apply for Schedule E purposes.

The Streamlined path for people behind on filings

If you've lived in Japan for a while and haven't been filing US taxes, the Streamlined Filing Compliance Procedures are usually the right way forward. Three years of federal returns, up to six years of FBARs, and a non-willful certification. The penalties that would otherwise apply are waived.

For Japan-resident Americans, the 330-day physical-presence test is almost always met, which makes the Foreign Offshore variant (SFOP) available, which is the cleaner of the two versions.

How we actually work

Send us a short description of your situation: length of time in Japan, employer type (direct-hire vs. contractor vs. business-owner), any foreign brokerage or mutual fund holdings, filing history. We respond within two Asia business days with whether Streamlined or standard annual filing fits, what the approximate scope looks like, and what a reasonable fee range is.

Get in touch