Essential Tax Deductions Every Taxpayer in Japan Should Know

Furusato Nozei (ふるさと納税)

Furusato nozei, or “hometown tax,” is one of the most popular tax optimization strategies in Japan. It is technically a donation to regional municipalities, but it functions as a way to redirect your resident tax while receiving gifts in return.

How It Works

1. You donate to municipalities of your choice through platforms like Furusato Choice, Rakuten Furusato Nozei, or Satofull.
2. You receive regional specialty gifts (food, crafts, experiences) worth roughly 30% of your donation amount.
3. The donation amount minus ¥2,000 is deducted from your income tax and resident tax the following year. Effectively, you pay ¥2,000 out of pocket and receive gifts worth much more.

Donation Limits

Your maximum effective donation (where you get the full tax benefit) depends on your income and family situation. General guidelines:

One-Stop Exception (ワンストップ特例)

If you donate to five or fewer municipalities and do not need to file a tax return for other reasons, you can use the One-Stop Exception. Instead of filing a return, you submit a simple form to each municipality, and the deduction is applied directly to your resident tax. This is the easiest path for salaried employees.

Medical Expense Deduction (医療費控除)

If your total medical expenses for the year exceed ¥100,000 (or 5% of your income if less than ¥2,000,000), you can deduct the excess from your taxable income. The maximum deduction is ¥2,000,000.

What Counts as Medical Expenses

• Doctor and hospital fees (co-payments after insurance)
• Dental treatment (including orthodontics if medically necessary)
• Prescription medications
• Transportation costs to medical facilities (public transit or taxi if necessary)
• Childbirth expenses (minus any insurance reimbursements or lump-sum birth allowance)
• Nursing care expenses
• Corrective lenses prescribed by a doctor (contact lenses, glasses)

What Does NOT Count

• Cosmetic surgery
• Health checkups (unless a condition is discovered and treated)
• Vitamins and supplements
• Private hospital room charges (差額ベッド代) unless medically required

Self-Medication Tax System (セルフメディケーション税制)

As an alternative to the standard medical expense deduction, you can use the self-medication system if your qualifying OTC drug purchases exceed ¥12,000 per year. The maximum deduction is ¥88,000. You must have received a preventive health checkup during the year to qualify. You cannot use both deductions — choose whichever gives you a larger benefit.

Mortgage Deduction (住宅ローン控除)

The housing loan deduction (住宅借入金等特別控除) is one of the most valuable tax credits in Japan. Unlike most deductions that reduce taxable income, this is a direct tax credit that reduces your tax bill yen for yen.

Eligibility

• You purchased or built a home for personal residence
• The home’s floor area is 50m² or more (40m² for certain new construction)
• You have a mortgage with at least 10 years remaining
• Your combined income is ¥20,000,000 or less
• You moved in within 6 months of purchase/construction

Credit Amount and Duration

For homes acquired in recent years:

For example, a ¥40,000,000 mortgage on a new energy-efficient home would yield a tax credit of ¥280,000/year (0.7% × ¥40M) for 13 years, totaling up to ¥3,640,000 in tax savings.

Small Business Mutual Aid (小規模企業共済)

The Small and Medium Enterprise Mutual Aid system (小規模企業共済) is a retirement savings plan for sole proprietors and small company directors. It is often described as “iDeCo for business owners.”

Who Is Eligible

• Sole proprietors (個人事業主)
• Directors of companies with 20 or fewer employees (5 for service industries)
• Freelancers

Contribution Limits

Monthly contributions range from ¥1,000 to ¥70,000, in ¥500 increments. The annual maximum is ¥840,000.

Tax Benefits

• Contributions are 100% deductible as a “small enterprise mutual aid deduction” (小規模企業共済等掛金控除), not an income deduction.
• At maximum contribution, you save roughly ¥250,000–370,000 in taxes annually, depending on your income bracket.
• Payout upon retirement is taxed favorably as either retirement income (退職所得) or annuity income (雑所得), both of which receive generous deductions.

iDeCo (個人型確定拠出年金)

iDeCo is Japan’s individual defined contribution pension plan. It offers a triple tax advantage: contributions are deductible, investment gains are tax-free, and payouts receive favorable taxation.

Contribution Limits by Employment Type

Tax Benefits

• Deductible contributions: Entire contribution is deductible under the small enterprise mutual aid deduction category (小規模企業共済等掛金控除).
• Tax-free growth: Investment returns within iDeCo are not taxed (no capital gains tax, no dividend tax).
• Favorable payout: Lump-sum withdrawal is taxed as retirement income (large deduction), annuity payments receive the public pension deduction.

Life Insurance Deduction (生命保険料控除)

Premiums paid for qualifying life insurance, medical/nursing care insurance, and individual annuity insurance are deductible. The deduction applies in three categories:

Your insurance company will send a deduction certificate (控除証明書) each fall. Submit this with your year-end adjustment or tax return.

Social Insurance Deduction (社会保険料控除)

All social insurance premiums you pay are fully deductible with no upper limit. This includes:

• National Health Insurance (国民健康保険)
• National Pension (国民年金)
• Employees’ Health Insurance (健康保険) and Pension (厚生年金) — your share
• Employment insurance (雇用保険) — your share
• Nursing care insurance (介護保険)

For freelancers paying National Health Insurance and National Pension, this deduction can easily exceed ¥800,000–1,500,000 per year, making it one of the largest deductions available.

You can also deduct social insurance premiums you pay on behalf of family members living with you (e.g., paying your spouse’s National Pension).

Spousal Deduction (配偶者控除)

If your spouse earns below certain thresholds, you may be eligible for the spousal deduction or the special spousal deduction (配偶者特別控除).

Standard Spousal Deduction

Available when your spouse’s total income is ¥480,000 or less (equivalent to about ¥1,030,000 in employment income after the employment income deduction). The deduction amount depends on your income:

Special Spousal Deduction

If your spouse’s income exceeds ¥480,000 but is under ¥1,330,000, you can claim the special spousal deduction. The amount decreases gradually as your spouse’s income increases. This phase-out range means there is no sudden “cliff” where a small increase in spousal income causes a large tax hit.