Japan Tax Checker is a free, English-language tool and guide for foreign residents facing the annual question: do I need to file a 確定申告 (kakutei shinkoku), and would filing get me money back? It turns your situation into a likely answer with the reason for each rule.
How the rules are sourced
Every rule the checker encodes carries a dated source from 国税庁 (the National Tax Agency, NTA) — the 20万円 rule, the ¥20,000,000 salary rule, 年末調整 coverage, the ふるさと納税 one-stop conditions, the medical-expense threshold, and more. Sources are recorded in the tool's data files and linked from each result. Where a rule has known edge cases the tool does not model — non-resident (非居住者) splits, tax-treaty positions, foreign-asset reporting — the output says so explicitly rather than guessing.
What it deliberately doesn't do
The checker models common resident cases. It does not attempt dual-status year splits, non-permanent-resident remittance rules, the exit tax, or treaty positions — these genuinely need a professional. Telling you honestly where the tool stops is part of the point.
Independence
This is an independent project, not affiliated with the National Tax Agency or any government body. It is informational only and not financial or tax advice. Always confirm your own situation before filing.
Go to the checker →