Employee Taxes in Japan

For the vast majority of people working in Japan, taxes are practically invisible. As a company employee ( 会社員 (かいしゃいん) , kaishain), you rarely have to touch a tax return or visit a tax office. Your employer calculates, withholds, and pays both your national income taxes and local residence taxes automatically.

However, “automated” does not mean “optimized.” If you do not understand how your paycheck is processed, you may miss out on substantial legal refunds, fail to declare dependents, or get into hot water with your company if you earn side income.

Here is a guide to how employee taxes work in Japan, how to read your annual tax slip, and when you are still required to file a tax return yourself.

1. Monthly Payroll Withholding ( 源泉徴収 (げんせんちょうしゅう) , Gensen Chōshū)

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Every month when your company issues your paystub ( 給与明細 (きゅうよめいさい) , kyūyo meisai), your compensation is split into two halves: what you earned ( 支給 (しきゅう) ) and what was deducted ( 控除 (こうじょ) ).

Because your employer does not know your exact final annual bonuses, deductions, or medical expenses throughout the year, the monthly income tax withheld is simply an educated estimate based on the government’s monthly withholding tax table.

2. Year-End Tax Adjustment ( 年末調整 (ねんまつちょうせい) , Nenmatsu Chōsei)

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Every November, HR departments across Japan distribute the famous annual tax paperwork. This process is called Nenmatsu Chōsei.

Its purpose is simple: reconcile the difference between the estimated income taxes withheld from January to December and your actual tax liability based on your finalized deductions.

The Key Deductions You Declare in November:

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1. Dependent Allowance ( 扶養控除 (ふようこうじょ) ): Supporting family members aged 16 or older (including parents living in Japan or overseas, subject to remitted support proof).
2. Spouse Allowance ( 配偶者控除 (はいぐうしゃこうじょ) ): Eligibility depends on both partners’ income. For 2026, the standard deduction’s spouse-income limit is ¥620,000 (¥1,360,000 if salary is the only income). The claimant’s deduction tapers above ¥9 million of total income and ends above ¥10 million. A separate special spouse deduction may apply. See the NTA spouse rules.
3. Private Life & Earthquake Insurance ( 生命保険料控除 (せいめいほけんりょうこうじょ) ): If you pay for private life, medical, or earthquake insurance in Japan, your insurers mail you a certificate in October. Attach this postcard to your form!
4. Housing Loan Deduction ( 住宅借入金等特別控除 (じゅうたくかりいれきんとうとくべつこうじょ) ): From your second year of an active Japanese home mortgage onward, this massive tax credit is applied directly via Nenmatsu Chōsei.
5. iDeCo / DC Pension Contributions: Monthly private pension contributions can be certified with the certificate mailed by the National Pension Fund Association.

The December “Bonus” ( 還付金 (かんぷきん) , Kanpukin)

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The adjustment can produce a refund or additional tax to collect. Your payroll team will reconcile the annual liability against amounts already withheld; the payment month depends on the employer.

3. Deciphering Your Withholding Slip ( 源泉徴収票 (げんせんちょうしゅうひょう) )

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In January, your company will hand you an A5-sized paper (or digital PDF) packed with small numbers called the Gensen Chōshū Hyō.

Keep this document safe. You will need it whenever you apply for an immigration visa renewal, rent an apartment, apply for a mortgage, or file a tax return.

4. When Must an Employee File a Tax Return ( 確定申告 (かくていしんこく) )?

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Even if your company completes Nenmatsu Chōsei for you, you are legally required (or strongly incentivized) to file a Final Tax Return during the usual February 16 to March 15 filing period (dates shift for weekends and holidays) if you meet any of the following criteria:

• Your annual gross salary exceeds ¥20,000,000: High earners cannot use Nenmatsu Chōsei and must file individually.
• Side income ( 副業 (ふくぎょう) , fukugyō) profit exceeds ¥200,000: The usual exception for an employee with one salary source and year-end adjustment has conditions. Even when an income-tax return is unnecessary, a residence-tax declaration may still be needed. If you file an income-tax return to claim a refund, include reportable side income below ¥200,000 too. See NTA employee filing rules.
• First year of a Home Mortgage ( 住宅ローン控除 (じゅうたくろーんこうじょ) ): In year 1 of buying a home in Japan, you must submit the deed and bank loan balance directly to the tax office via Kakutei Shinkoku.
• Medical expenses exceeded ¥100,000 ( 医療費控除 (いりょうひこうじょ) ): Qualifying expenses after reimbursements may support a deduction; lower-income taxpayers can have a lower threshold. Claiming a deduction is different from being required to file.
• You donated to more than 5 municipalities for Furusato Nōzei: (Or failed to submit the One-Stop Special forms before January 10th).
• You work for a foreign employer without Japanese payroll: If your employer does not have a registered legal branch in Japan, no taxes are withheld at source, and you must declare your total income yourself.

5. Residence Tax on Side Income

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For non-salary side income, the tax-return form lets you request ordinary collection ( 普通徴収 (ふつうちょうしゅう) ), meaning payment directly to your municipality. Look for the residence-tax collection option for income other than employment or public pensions.

This is a collection preference, not a guarantee of privacy from an employer. Municipal procedures differ, and side-job salary may be combined with the main salary for payroll collection. Check your municipality’s rules and your employment contract. Shinjuku explains its collection treatment here.