Do I need to file a tax return in Japan?

When you probably do not need to file

If you are a single-employer salaried worker with taxes withheld and your employer completed your year-end adjustment (年末調整), your income tax is usually already settled and no return is needed. The year-end adjustment handles standard deductions and reconciles what was withheld.

When you must (or should) file

You generally must file a 確定申告 if you have more than ¥200,000 of side income, two or more employers, self-employment or business income, or large investment/crypto gains not otherwise settled. You should also file — even when not required — to claim deductions like significant medical expenses, the first-year mortgage credit, or donations (including some Furusato Nozei cases). For 2025 income, filing ran February 16–March 16, 2026 through e-Tax, with records for each deduction. Check the NTA for the applicable year rather than reusing these dates.

Records, e-Tax, and when to get help

Keep each employer’s withholding slip (源泉徴収票), My Number details, deduction certificates, donation or medical-expense records, and bank details for a refund. e-Tax is the NTA filing channel; resident tax is administered by your municipality and normally follows the income information reported nationally. Health-insurance premiums and pension contributions are separate social-insurance systems, not resident tax, even when they appear beside tax on a payslip.

Ask a licensed tax accountant before filing if you have foreign income or assets, unclear residency, multiple countries, a business, crypto transactions, a notice from an authority, or cannot reconcile withholding. Ask your municipality about resident-tax billing and your employer, insurer, pension office, or Japan Pension Service about social-insurance and pension records.