Japan's self-assessment return covers a calendar year and is filed in a window that runs from about 16 February to 15 March of the following year; for 2026 income, that is 16 February to 15 March 2027. Tax due is paid by the same deadline. The return can be filed online through the National Tax Agency's e-Tax system, and the inhabitant tax is then calculated from it, so a separate local return is usually unnecessary.
Salaried employees are mostly settled by the year-end adjustment. They must file a return if their salary exceeds 20 million yen, if their income other than salary is more than 200,000 yen, if they received pay from two employers and only one adjusted it, or if their pay was not adjusted at all, for example because they joined late in the year or left mid-year without a new job. Many others file voluntarily, to claim medical expenses, donations or the first year of a mortgage deduction. A return claiming only a refund can be filed for up to five years.
Leaving Japan has its own rule. A resident who leaves before the filing season must either file before departure or appoint a tax agent in Japan, who files and pays on their behalf. Residents with financial assets of 100 million yen or more can also face an exit tax on unrealised gains when they leave.
What it means for a foreign employer
- Most senior hires will file. Above 20 million yen of salary, and for almost anyone with equity awards from a foreign parent, a return is required. Many employers pay for tax preparation as a benefit.
- Foreign income makes it harder. Rental income at home, overseas investments and foreign pensions all go on the Japanese return for residents taxed on worldwide income.
- Departing staff need a plan. An assignee or foreign hire who leaves in the middle of a year should appoint a tax agent before going, or the final return may be missed.
- Returns support visa and residency files. A clean tax record helps later applications for extensions and permanent residency.
Sources
- Income Tax Act, Articles 120, 121, 122 and 127; Article 60-2 (exit tax).
- National Tax Agency, guidance on who must file and on filing periods for 2026 income.