A tax return (確定申告 - Kakutei Shinkoku) is the self-assessed method of reporting income to the National Tax Agency for the purposes of calculating how much income tax is due to be paid or refunded.
If any of the follow apply to you. you will need to file this tax return instead of, or in addition to, the end of year tax adjustment your company will/may do for you:
- You earn over 20 million yen
- You have medical expenses over 100,000 yen for the year.
- You have 'donated' using Furusato Nozei but have not used the one-stop system.
- You have other sources of income to declare besides your main employment, such as overseas stock gains or rents, or the sale of some assets.
- You have a Home Loan Interest Tax Deduction (From Year 2 onwards this can be claimed through the end of year tax adjustment)
- 2021 Income Tax Guide from the National Tax Agency
- NTA Tax Answer article #2020 (Japanese)
- Reasons to declare investment income (Reddit)
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