Japanese Tax Return Guide for Foreign Sole Proprietors and Self-Employed Individuals

Hello, my name is Taisei Koshida, a certified public accountant and licensed tax accountant in Japan.

If you are self-employed or operate as a sole proprietor in Japan, you may need to file an annual Japanese income tax return, known as kakutei shinkoku (確定申告).

For foreign business owners, preparing a Japanese tax return involves more than adding up sales and expenses. You need to determine your business income, identify deductible expenses, maintain proper accounting records, consider whether the Blue Form (Aoiro Shinkoku) applies, and file the return by the applicable deadline.

Foreign residents can also have additional issues when they receive income from overseas, use foreign bank accounts or credit cards, or have investments and other assets outside Japan.

This guide explains the basic Japanese tax filing process for foreign sole proprietors and self-employed individuals, from bookkeeping during the year to filing the annual tax return.

1. Who Needs to File a Japanese Tax Return?

If you operate your own business as an individual in Japan, you may need to file an annual Japanese income tax return, or kakutei shinkoku.

Whether you are actually required to file depends on your income, deductions, withholding tax, other sources of income, and your individual circumstances. Having business sales does not automatically mean that income tax is payable.

Even when the business makes a loss, filing a tax return can still be important.

If you use the Blue Form (Aoiro Shinkoku) and meet the applicable requirements, a qualifying net loss can generally be carried forward for up to three years and offset against future income.

This can be particularly useful for a new business that makes a loss in its first year and becomes profitable later.

For more information, see
Blue Form (Aoiro Shinkoku) in Japan: Benefits and Deadlines.

2. How Is Business Income Calculated for a Sole Proprietor in Japan?

For a sole proprietor, the starting point is generally the income earned from the business minus deductible business expenses.

However, your taxable income is not simply the amount of cash left in your bank account at the end of the year.

The timing of sales and expenses matters. Money received in January can relate to work performed in December, and an item purchased during the year may need to be treated as a fixed asset and depreciated rather than deducted entirely at once.

Personal withdrawals from the business account are also not automatically business expenses, and money transferred between your own accounts is not business income simply because it appears as a deposit.

This is why bookkeeping should identify the nature of each transaction rather than simply total the money coming into and going out of the bank account.

3. When Is the Japanese Tax Return Deadline?

For an individual sole proprietor or self-employed person, Japanese income tax is calculated on a calendar-year basis from January 1 to December 31.

The annual income tax return and payment are generally due by March 15 of the following year.

For example, income earned during 2026 is generally reported by March 15, 2027.

If March 15 falls on a Saturday, Sunday, or certain public holidays, the statutory deadline moves to the next applicable business day.

If you operate through a company rather than as an individual, the rules are different. A Japanese corporation generally files its corporate tax return within two months after the end of its fiscal year.

Individual consumption tax also has a different filing deadline, so a sole proprietor who is subject to consumption tax needs to deal with the income tax return and consumption tax return separately.

4. What Records Do You Need for a Japanese Tax Return?

A Japanese tax return starts with the accounting records maintained during the year.

For a typical small business, the records may include:

• Sales and customer information
• Business expenses
• Invoices and receipts
• Japanese and overseas bank account transactions used for the business
• Business credit card transactions
• Wise or other payment service transactions
• Foreign-currency transactions
• Fixed asset purchases
• Other income and tax-related documents relevant to the return

The amount of information required depends on the business. A freelancer with a small number of transactions does not need the same bookkeeping process as a business with hundreds of transactions, several accounts, employees, and fixed assets.

For a practical explanation of what to keep, see
Bookkeeping in Japan: What Records Foreign Business Owners Actually Need.

5. Do You Need Accounting Software?

Accounting software is not always necessary.

For a small and straightforward business, an Excel spreadsheet or similar system can be sufficient if the required information is recorded correctly and the supporting documents are properly retained.

However, accounting software becomes much more useful when the business has many transactions, several bank accounts, credit cards, fixed assets, employees, or consumption tax obligations.

Software itself does not determine whether your accounting is correct. The important point is whether the underlying transactions are recorded and classified properly.

6. What Is the Blue Form (Aoiro Shinkoku)?

The Blue Form, known as Aoiro Shinkoku (青色申告), is an optional tax filing system for qualifying business owners in Japan.

It provides several tax advantages if you apply within the applicable deadline and maintain the required accounting records.

Depending on the circumstances, the benefits can include:

• A special deduction from business income
• The ability to carry qualifying net losses forward
• Special treatment for certain salaries paid to family members

The Blue Form is not automatic. An application must be submitted within the applicable deadline.

For the ¥650,000 Blue Form special deduction, using accounting software alone is not enough. The requirements include proper bookkeeping under the regular method, generally double-entry bookkeeping, preparation of a balance sheet and profit and loss statement, filing by the statutory deadline, and either filing the return through e-Tax or meeting the applicable electronic bookkeeping requirements.

The Blue Form rules should therefore be checked when the business starts rather than for the first time just before the first tax return. If the application deadline has already passed, some benefits may not be available for that year.

For details, see
Blue Form (Aoiro Shinkoku) in Japan: Benefits and Deadlines.

7. What Business Expenses Can You Deduct in Japan?

One of the most common questions from self-employed clients is: Can I deduct this as a business expense?

The starting point is whether the expense is genuinely related to the business.

Typical business expenses can include:

• Transportation
• Communication costs
• Office expenses
• Professional fees
• Business-related meals
• Software and online services used for the business

However, not every payment made while operating a business is automatically deductible.

Some expenses contain both business and personal elements. If part of your home, phone, internet connection, or car is used for both business and private purposes, the expense may need to be divided based on the actual business use.

Timing also matters. Some purchases cannot be deducted entirely in the year of payment and instead need to be recorded as assets and depreciated over time.

Good accounting is therefore not simply about collecting receipts. You need to identify what the payment was for and determine the correct tax treatment.

For more information, see
Expenses to Be Mindful of When Recording Them in Japan
and
Can Business Setup Costs Be Deducted as Expenses in Japan?.

8. What If You Do Not Have a Receipt?

A receipt is important evidence, but losing one receipt does not automatically mean that the expense can never be deducted.

The important point is whether you can establish that the payment was actually made for a business purpose.

Depending on the circumstances, an invoice, bank record, credit card statement, email, contract, or other contemporaneous record may help support the transaction.

Missing documentation should be the exception, not the normal way of keeping business records.

For more information, see
Can You Deduct a Business Expense Without a Receipt in Japan?.

9. What Information Is Needed to Prepare the Tax Return?

Once the bookkeeping is complete, the next step is to collect the information needed for the tax return itself.

Depending on your situation, this can include:

• Final business income and expense records
• Balance sheet information, if required
• Fixed asset and depreciation information
• Withholding tax certificates and payment records
• Social insurance and pension information
• Medical expense information where applicable
• Insurance deduction certificates
• Information about other income earned during the year
• Foreign income and foreign tax information, where applicable

Collecting these documents only a few days before the filing deadline can make the return unnecessarily difficult. The business accounting should therefore be brought up to date before the tax return preparation begins.

For another practical checklist, see
Necessary Information for Tax Returns for Sole Proprietors in Japan.

10. Foreign Income Can Make the Japanese Tax Return More Complicated

Foreign residents who operate a business in Japan sometimes also receive income from outside Japan.

Examples include:

• Salary or consulting income from overseas
• Foreign dividends and interest
• Capital gains on overseas investments
• Foreign rental income
• Income from an overseas company or LLC
• Retirement income or pension-related distributions

These items should not simply be added to the sole-proprietor business income.

The Japanese tax treatment can depend on your tax residency status, the category and source of the income, when the income arose, whether funds were remitted to Japan, foreign taxes paid, and applicable tax treaty rules.

International tax issues therefore need to be separated from the ordinary bookkeeping and business-income calculation.

For Americans living in Japan, see
Moving to Japan? How Your U.S. Income Is Taxed in Japan.

11. What Happens If You Do Not File a Tax Return?

If you are required to file a Japanese tax return but fail to do so, the tax office can later investigate your income and business records.

If unpaid tax is found, the original tax can be accompanied by additional tax and late-payment charges.

The practical problem also becomes larger as time passes. Several years later, it can be difficult to reconstruct old bank transactions, sales records, invoices, receipts, and the purpose of individual payments.

Dealing with an unfiled return several years later is usually much more troublesome than preparing the accounting records and return properly from the beginning.

For more information, see
Drawbacks of Not Filing Taxes in Japan.

12. Frequently Asked Questions About Japanese Tax Returns for Foreign Sole Proprietors

Do I Need Accounting Software to File a Japanese Tax Return?

No. A small and straightforward business can maintain its accounting records using Excel or another suitable system if the necessary information is recorded correctly.

Accounting software becomes more useful as the number of transactions, bank accounts, credit cards, fixed assets, and tax issues increases.

I Started My Business in the Middle of the Year. Do I Only Report Income After I Registered the Business?

Not necessarily. The tax treatment does not depend only on the date written on the business registration form.

The actual timing of the business activity, income, and related expenses needs to be considered.

My Business Made a Loss in Its First Year. Should I Still File a Tax Return?

Filing can still be important. If you qualify for the Blue Form and meet the applicable requirements, a qualifying net loss can generally be carried forward for up to three years and offset against future income.

This can make the first-year return important even when no income tax is currently payable.

Can I Deduct Expenses I Paid With My Personal Credit Card?

Using a personal credit card does not by itself determine whether an expense is deductible. The important question is whether the payment was genuinely made for the business and whether the transaction can be properly supported and recorded.

However, separating business and personal transactions makes bookkeeping much easier and reduces confusion later.

I Have a Full-Time Job and a Side Business. Do I Need to File a Tax Return?

It depends on the amount of your side-business income and your overall tax situation.

If you receive salary from one employer, your annual salary is ¥20 million or less, and your salary is subject to withholding and year-end adjustment, you generally do not need to file an income tax return if your total income other than salary and retirement income is ¥200,000 or less.

The ¥200,000 threshold generally refers to income, not gross sales. For a side business, this means that the relevant amount is generally calculated after deducting necessary business expenses from the revenue.

However, if you file an income tax return for another reason, such as claiming a medical expense deduction, income of ¥200,000 or less must also be included in the return. Other filing requirements can also apply depending on your circumstances.

I Also Earn Income Overseas. Can It Be Included in the Same Calculation as My Japanese Business?

Not automatically. Foreign salary, dividends, capital gains, rental income, LLC income, pensions, and other foreign income can have different Japanese tax treatments.

They should first be classified correctly before determining how they are reported on the Japanese tax return.

13. Accounting and Tax Support for Self-Employed Individuals in Japan

Koshida Accounting and Tax Office provides accounting and tax services in Japan with English support.

We assist foreign sole proprietors, freelancers, entrepreneurs, and small business owners with bookkeeping, accounting in Japan, kakutei shinkoku, Blue Form tax returns, deductible expenses, and other Japanese tax matters.

Some clients need bookkeeping and accounting support throughout the year. Others maintain their own records and need assistance only with the annual Japanese tax return or a particular tax issue.

If your situation also involves overseas income, foreign assets, a U.S. LLC, foreign tax credits, or remittance-based taxation, those international tax issues can be reviewed together with your Japanese tax return.

For a broader guide to operating a business in Japan, see
Starting & Running a Business in Japan: Tax and Accounting Guide for Foreign Business Owners.

If you need assistance with your bookkeeping or Japanese tax return, please
contact Koshida Accounting and Tax Office through the inquiry form.