The Complete Guide to Filing Taxes in Japan as a Foreigner

What is 確定申告? かくていしんこく

確定申告 (kakutei shinkoku) is Japan's annual individual income tax return — the equivalent of the US Form 1040 or the UK Self Assessment. The word literally translates to "final declaration," because it is your final settlement of income tax for the year.

Unlike many countries where nearly everyone files a tax return, Japan's system is designed so that most salaried employees never have to touch a tax form. Your employer withholds income tax from every paycheck (源泉徴収 / gensen chōshū) and then performs a year-end adjustment (年末調整 / nenmatsu chōsei) in December to reconcile the total. If everything matches, you are done — no filing required.

But if you fall outside that neat system — freelancing, multiple jobs, high income, special deductions — you need to file 確定申告 yourself. The return covers all income earned from January 1 to December 31 of the previous year. So for tax year 2025, you file during early 2026.

Japan uses a self-assessment system (申告納税制度), meaning it is your responsibility to calculate your own tax, file the return, and pay any balance owed. The tax office (税務署 / zeimusho) does not send you a bill — you must take action yourself.

Do you need to file? 確定申告が必要？

This is the first question every foreigner in Japan asks — and the answer depends on your employment type, income level, and whether you want to claim certain deductions. Use the table below to find your situation.

A good rule of thumb: if you had any income that your employer did not already account for and withhold tax on, you probably need to file. When in doubt, filing is almost always better than not filing — if you overpaid tax during the year, you will get a refund.

Key deadlines 申告期限

The tax filing season in Japan is short and fixed. Unlike some countries that give you months to file, Japan compresses everything into roughly one month. Mark these dates in your calendar.

Pro tip: if you are expecting a refund (還付申告), you can file as early as January 1. Refund-only returns are not subject to the February 16 start date. Filing early means you get your refund sooner — typically within 3 weeks via e-Tax, or 1-2 months via paper filing.

How to file 申告方法

There are three ways to file your 確定申告 in Japan. Each has its pros and cons, but e-Tax is increasingly the recommended method — especially for foreigners who want to avoid long queues and Japanese-only paper forms.

Method 1: e-Tax (online filing) — Recommended

e-Tax is the National Tax Agency's online filing system. It is the fastest and most convenient way to file. You can complete your entire return from home, and refunds are processed faster (about 3 weeks versus 1-2 months for paper).

What you need:

• ● マイナンバーカード (My Number Card) — the plastic IC card, not just the notification paper
• ● IC card reader or a smartphone with NFC (iPhone 7+ or most Android phones) to read the card
• ● Your 源泉徴収票 (withholding tax slip) from each employer
• ● Receipts and certificates for any deductions you want to claim

Step-by-step process:

1. Go to the 確定申告書等作成コーナー — Visit the NTA's online return preparation site at keisan.nta.go.jp. The site has partial English support but is primarily in Japanese.
2. Create or log in to your e-Tax account — If it's your first time, you will register using your マイナンバーカード. Hold the card to your phone or reader when prompted.
3. Select the return type — For most foreigners, this is 所得税 (income tax). Choose the appropriate form based on your income types.
4. Enter your income — Input figures from your 源泉徴収票. If you have freelance income, enter your revenue (売上) and expenses (経費) here.
5. Enter deductions — Add any deductions you are claiming: medical expenses, social insurance, life insurance, ふるさと納税 donations, etc.
6. Review the calculation — The system automatically calculates your tax. If the result is negative, you get a refund. If positive, you owe additional tax.
7. Submit electronically — Authenticate with your マイナンバーカード and submit. You will receive a confirmation receipt number.
8. Pay any tax owed — You can pay via bank transfer, credit card, convenience store (コンビニ), or direct debit (振替納税). Refunds are deposited directly into your bank account.

Method 2: In person at the tax office (税務署)

You can visit your local tax office during the filing period to file in person. Staff members can help you fill out the forms, and some offices have computers set up for e-Tax filing with assistance.

• ● Pros: Staff can help with complicated situations; you can ask questions face-to-face
• ● Cons: Long queues (especially in the last week of March), limited English support, you may need to take time off work
• ● Bring: マイナンバーカード (or notification + ID), 源泉徴収票, all receipts, your seal (印鑑) or signature, bank account details for refund

Some larger cities set up temporary filing centers (確定申告会場) during the busy season. These are separate from the regular tax office and are specifically staffed for high-volume filing assistance. Check the NTA website for locations near you.

Method 3: Filing by mail (郵送)

You can download the tax return forms from the NTA website, fill them out by hand or print from the online preparation tool, and mail them to your jurisdictional tax office. The postmark date counts as the filing date, so mailing on March 15 is acceptable.

• ● Pros: No queues, no マイナンバーカード reader needed
• ● Cons: Slowest refund processing (1-2 months), risk of errors without real-time validation, you need to know which tax office to send it to
• ● Tip: Use the online preparation tool to generate your forms, then print and mail. This way the calculations are done for you, and you just sign and send.

Income types 所得の種類

Japan classifies income into 10 categories. Each category has its own calculation rules, and some are taxed differently than others. Understanding which category your income falls into is essential for filing correctly.

Common deductions 所得控除

Deductions (控除 / kōjo) reduce your taxable income, which directly lowers the amount of tax you pay. Japan offers a generous set of deductions — but you need to know about them and claim them. Your employer handles some via 年末調整, but others require you to file 確定申告.

Note that 住宅ローン控除 is technically a tax credit (税額控除), not a deduction (所得控除). This means it directly reduces your tax bill rather than reducing your taxable income — making it even more valuable. For the first year, you must file 確定申告 to claim it; from the second year onward, your employer can handle it via 年末調整.

Common mistakes foreigners make よくある間違い

Filing taxes in a foreign language and system is inherently confusing. Here are the five most common mistakes we see foreigners make — and how to avoid them.

• 1.
  Not filing when required. Many foreigners assume their employer handles everything. If you had side income over ¥200,000, changed jobs without 年末調整, or freelanced on the side, you are legally required to file. Ignorance is not an excuse — the NTA can and does audit foreigners. (所得税法第120条)
• 2.
  Forgetting about 住民税 for side income under ¥200,000. The ¥200,000 side income threshold only exempts you from filing national 確定申告 — it does NOT exempt you from 住民税 (resident tax). You need to file a separate 住民税 return at your local ward office, or you may face an unexpected tax bill.
• 3.
  Missing deductions they are entitled to. Medical expenses, social insurance, ふるさと納税, iDeCo contributions — these all reduce your tax bill, but only if you claim them. Many foreigners leave money on the table simply because they did not know a deduction existed. Always review the full list of 所得控除 before submitting.
• 4.
  Not understanding tax residency status. Japan taxes residents on worldwide income and non-residents only on Japan-source income. If you have been in Japan for 5+ years (with some nuance around the "non-permanent resident" category), you are taxed on everything — including overseas investment gains, foreign rental income, and remote work for overseas clients. (所得税法第7条)
• 5.
  Filing ふるさと納税 incorrectly when also filing 確定申告. If you used the ワンストップ特例 (one-stop exception) for ふるさと納税 but then also file 確定申告 for another reason, the one-stop exception is automatically invalidated. You must re-enter all your ふるさと納税 donations in the 確定申告 return, or you lose the deduction entirely.

Frequently asked questions よくある質問