[① Overview] How Japan's Tax System Works — The "Residency Classification" Foreign Residents Should Understand First

Anyone who earns income in Japan has a tax obligation, regardless of nationality. However, for foreign nationals, the scope of income taxed in Japan differs depending on their length of stay. If you handle assets or remittances from your home country without understanding this "residency classification," it can lead to unexpected taxation or failure to file required returns.

This series consists of 4 articles. After grasping the overall picture in this overview article, please proceed to the article that matches your situation.

This article is intended to provide general information and is not a substitute for individual tax consultation. Amounts are based on laws and regulations as of August 2026 (Reiwa 8).

1. Three Types of Individual Burdens in Japan

Type Taxing Authority Characteristics Approximate Rate Income Tax National Government Progressive taxation 5–45% Resident Tax Prefecture/Municipality Mostly uniform Income-based portion 10% + Per capita portion approx. ¥5,000 Social Insurance Premiums National/Local Government Not technically a tax, but mandatory Approx. 15% of salary (employee's share)

Social insurance premiums are not technically taxes, but their impact on take-home pay is often greater than income tax, so in practice they should be considered together.

One of the most misunderstood points in Japan's system is that resident tax is levied in the following year based on the previous year's income. This explains why residents don't pay resident tax in their first year in Japan, why take-home pay suddenly drops in the second year, and why a payment notice arrives the year after someone retires or leaves Japan.

1. Three Categories of Taxpayers

Under Japan's Income Tax Act, individuals are divided into three categories, each with a different scope of taxable income. This is the most important part of this series for foreign nationals.

Category Criteria Taxable Income Non-resident Person who does not qualify as a resident Only Japan-source income (in principle, 20.42% withholding tax at source) Non-permanent resident A resident who does not have Japanese nationality and has had a domicile or residence in Japan for a total of 5 years or less within the past 10 years All Japan-source income + Foreign-source income that is "paid in Japan" or "remitted from abroad" Permanent resident (resident other than a non-permanent resident) Residents other than the above Worldwide income "Resident" Status Is Not Determined by Residence Status

A "resident" is a person who has a domicile in Japan, or who has had a residence in Japan continuously for one year or more up to the present. This is determined by where a person's actual center of life is, not by the type of visa or the name of their residence status.

Similarly, "permanent resident" for tax purposes is a different concept from the "Permanent Resident" residence status under the Immigration Control Act. Under tax law, a permanent resident simply refers to a resident whose non-permanent resident period has ended.

1. Non-Permanent Residents and Overseas Remittances — A Common Pitfall

The non-permanent resident system is unique to Japan. It is an exceptional treatment in which, despite being a resident, foreign-source income is in principle excluded from taxation. However, if such income is paid in Japan or remitted to Japan, it becomes subject to taxation through a certain calculation.

Remittances Cannot Be "Offset"

In past tax tribunal rulings, it has been determined that even if funds remitted from abroad to Japan are sent back overseas within the same year, this amount cannot be deducted from the remitted amount. This is because the act of remittance itself is treated as the trigger for the exercise of taxing rights, so the idea that "sending money back and forth cancels it out" does not hold.

Cases Requiring Caution

If you send living expenses from an account in your home country to an account in Japan, be especially careful if any of the following apply to you:

You receive rental income from real estate in your home country You have dividend or capital gains income from a securities account in your home country You have business income or side income in your home country

If you remit money to Japan in a year when you have this kind of foreign-source income, taxation may arise up to the amount remitted. Be sure to keep records of your remittances.

Conversely, if you have no foreign-source income at all in a given year, remittances made that year are simply a transfer of assets and are not taxed.

When You Exceed 5 Years

Once your cumulative period in Japan exceeds 5 years (calculated within the past 10 years), your status switches from non-permanent resident to permanent resident, and your worldwide income becomes subject to taxation. This is a major turning point for those who own real estate or securities accounts in their home country. You should be aware of the year this switch occurs and, if necessary, review how you hold your assets in advance.

1. Ten Categories of Income

Japan's income tax law divides income into 10 categories based on the nature of the income.

Category Main Contents Employment income Salary and bonuses for company employees, part-time and temporary workers Business income Income from sole proprietorships and freelance work Real estate income Rental income Interest income Interest on savings and deposits Dividend income Stock dividends, investment trust distributions Capital gains Profits from the sale of real estate, stocks, etc. Occasional income Insurance maturity payments, prize winnings Miscellaneous income Public pension, side income, cryptocurrency gains Retirement income Retirement allowance Forestry income Income from logging or sale of forest land

Things are simple for those with only employment income, but if you have side income, rental income from property in your home country, or cryptocurrency gains, you may fall into multiple categories and be required to file a tax return.

1. Structure of Income Tax Calculation

① Amount of income − Necessary expenses (for salary, the employment income deduction) = Amount of income ② Amount of income − Income deductions = Amount of taxable income ③ Amount of taxable income × Tax rate = Income tax amount ④ Income tax amount − Tax credits = Base income tax amount ⑤ Base income tax amount + Special reconstruction income tax = Amount of tax payable

"Income (revenue)" and "income (taxable amount)" are different things. For an employee with an annual salary of ¥5 million, their taxable "income" is not ¥5 million. This distinction comes up repeatedly when determining eligibility for deductions.

Tax Rate Table (7-Bracket Progressive System) Taxable Income Tax Rate Deduction Amount ¥1,000 – ¥1,949,000 5% ¥0 ¥1,950,000 – ¥3,299,000 10% ¥97,500 ¥3,300,000 – ¥6,949,000 20% ¥427,500 ¥6,950,000 – ¥8,999,000 23% ¥636,000 ¥9,000,000 – ¥17,999,000 33% ¥1,536,000 ¥18,000,000 – ¥39,999,000 40% ¥2,796,000 ¥40,000,000 and above 45% ¥4,796,000

Because this is a progressive system, it will never happen that "your take-home pay decreases because your income increased and moved you into a higher tax bracket." Only the portion of income above each threshold is taxed at the higher rate.

Special Reconstruction Income Tax and Special Defense Income Tax

Currently, a 2.1% special reconstruction income tax is added on top of the income tax amount.

Under the Reiwa 8 tax reform, a new 1% special defense income tax will be introduced starting January of Reiwa 9. At the same time, to prevent a sudden increase in household burden, the special reconstruction income tax rate will be reduced from 2.1% to 1.1%, and the taxation period will be extended by 10 years to secure reconstruction funding.

1. Basic Structure of Resident Tax

Resident tax is levied on income earned from January 1 to December 31 of the previous year, by the municipality where the person resided as of January 1 of the current year.

Category Contents Income-based portion Approx. 10% of taxable income (6% municipal + 4% prefectural) Per capita portion Uniform amount of approx. ¥5,000 (¥4,000 resident tax per capita portion + ¥1,000 forest environment tax)

While there may be slight additional amounts depending on the municipality, the basic structure is the same nationwide.

This "January 1 rule" carries significant implications when leaving Japan. This will be covered in detail in Article ④, on departure and returning to Japan.

1. Tax Treaties — Not Automatically Applied

Japan has concluded tax treaties with many countries that eliminate double taxation and reduce or exempt certain types of income. Some treaties include tax exemption provisions for professors, researchers, students, and business trainees.

It is important to note that a notification must be filed in order to receive treaty benefits. In principle, an "Application Form for Income Tax Convention" must be submitted to the tax office, usually through the payer (such as your employer or university). Since the benefits are not applied automatically, there are many cases where people miss out on tax exemptions they were otherwise entitled to, simply because they failed to submit the required form.

You can check whether your home country's tax treaty with Japan includes relevant provisions by referring to the list of tax treaties published by the Ministry of Finance.

1. Which Article Should You Read Next?

Situation Recommended Article You receive a salary as a company employee, part-time, or temporary worker ② Company Employee Edition — Year-end tax adjustment, practical aspects of deductions, and the "annual income wall" You are a sole proprietor, freelancer, or have side income ③ Freelance/Side Income Edition — Filing tax returns, expenses, and consumption tax You plan to leave Japan due to returning home or a work transfer ④ Departure/Return Edition — Tax administrators, resident tax, and pension refunds

When renewing your residence status or applying for permanent residency, submission of a tax payment certificate is generally required. Paying taxes properly not only helps you avoid tax-related problems, but is also directly connected to protecting your foundation for living in Japan.