This is an English translation of our Japanese article. Rules and figures may change; the Japanese version and official sources are authoritative. For individual matters, consult a tax office or a licensed tax accountant (zeirishi).

Sole Proprietor's Tax Return Guide

Understand when, what, and how to file — starting from zero.

From deciding who needs to file, to preparing documents, bookkeeping, filing, and paying — everything sole proprietors and freelancers should know, all in one place.

What is a tax return?

The basics of why it's needed and who does it.

Basics

Who needs to file

A decision flow for a sole proprietor's filing obligation.

Check

Blue-form vs. white-form return

Which should you choose? Differences in deduction and effort.

Tax saving

Preparing the documents

What to gather, by category, in checklist form.

Prep

Filing steps (step by step)

From bookkeeping to filing, in order.

Steps

How to use e-Tax (e-filing)

Steps to file on a smartphone or a PC.

e-Tax

Easily missed income deductions

A checklist of deductions people often fail to claim.

Tax saving

Common mistakes and fixes

From missing entries and late filing to amended returns.

Caution

What is a tax return?

A tax return (kakutei shinkoku) is the procedure of calculating your income for the year from January 1 to December 31, and reporting and paying the income tax you owe yourself. For company employees, the employer handles this through the year-end adjustment, but sole proprietors and freelancers must do it themselves.

Filing period

Every year, February 16 to March 15
(if it falls on a weekend or holiday, the next business day)

What is calculated

The income (≒ profit) for the previous January 1 to December 31

Where to file

The tax office with jurisdiction over your place of tax payment (your address)
or file online via e-Tax

Payment deadline

Income tax is due by March 15
Direct debit (account transfer) is mid-April

The overall picture of a tax return
1
Daily bookkeeping
Jan–Dec
2
Gather documents
from Jan
3
Year-end adjustments
Jan–Feb
4
Prepare the return
Feb–Mar
5
File and pay
by 3/15
How income tax is calculated
Sales (revenue)
Necessary expenses
Business income
Various deductions
(blue-form special, basic, social insurance, etc.)
Taxable income
×
Tax rate
Income tax

* The income tax rate is 5–45% depending on taxable income (progressive taxation). On top of this, residence tax of 10% is levied separately.

Who needs to file

Sole proprietors and freelancers generally need to file a tax return, but the situation differs if your income is low or if it's combined with employment income. Check with the flow below.

Is your business income (sales − expenses)
over ¥580,000?
Yes (it's over)
Tax return required

Income tax applies to the amount exceeding the basic deduction (¥580,000), so a return is required.

No (¥580,000 or less)
△ Depends

Even if income tax is zero, a residence tax return may be required. Also, you can file if you want to receive a refund.

List of cases that require filing

Required
Business income exceeds ¥580,000 (the basic deduction)

The basic pattern for sole proprietors and freelancers. If business income = sales − expenses exceeds ¥580,000, a return is required.

Required
An employee with employment income earns over ¥200,000 from a side business

Even if your main job's year-end adjustment is done, a return is required if side-business income or miscellaneous income exceeds ¥200,000.

Required
You have real estate income, capital gains, or occasional income

Rental income and gains from selling land, buildings, or stocks are also added to your income.

Optional
You want to recover over-withheld tax (refund claim)

When you want to apply the medical expense deduction, mortgage deduction, or donation deduction (furusato nozei). Filing lets you receive a refund.

Optional
You want to carry a loss forward to the next year

With a blue-form return, you can carry a business loss forward for three years (carryover deduction of net losses). Filing is required to receive this benefit.

Why sole proprietors should file even with "zero income"

Even if the tax amount is zero, filing gets you an income certificate. This is needed in situations that require proof of income, such as mortgages, nursery school admission screening, and various subsidy applications.

Blue-form return vs. white-form return

There are two kinds of tax return: the blue-form return and the white-form return. For sole proprietors, we strongly recommend the blue-form return — it takes more effort but saves overwhelmingly more tax.

Comparison itemBlue-form returnWhite-form return
Prior notification Required (application for approval of blue-form return)
Within 2 months of starting business, or by December 31 of the prior year
Not required
Type of bookkeeping Double-entry bookkeeping (¥650,000 deduction)
or simple bookkeeping (¥100,000 deduction)
Single-entry bookkeeping (income statement form)
Special deduction Up to ¥650,000 (when using e-Tax) ¥0 (no deduction)
Loss carryover Can carry forward for 3 years Not possible
Salary to family Can be fully expensed as salary to a blue-form full-time family employee Capped (only a deduction of ¥860,000 for a spouse, ¥500,000 for others)
Equipment under ¥300,000 Can be expensed in a lump sum (special rule for small-amount depreciation) Depreciation is generally required
Effort Somewhat more (greatly reduced with accounting software) Relatively simple
Example: annual sales of ¥5 million and expenses of ¥2 million
White-form return
Sales¥5,000,000
Expenses−¥2,000,000
Special deduction¥0
Business income¥3,000,000
Basic deduction, etc.−¥730,000
Taxable income¥2,270,000
Income tax (10%) ≒ about ¥172,500
VS
Blue-form return (e-Tax)
Sales¥5,000,000
Expenses−¥2,000,000
Blue-form special deduction−¥650,000
Business income¥2,350,000
Basic deduction, etc.−¥730,000
Taxable income¥1,620,000
Income tax (5%) ≒ about ¥81,000
→ about ¥91,500 in tax savings!
Just switching to the blue-form return can save more than ¥90,000 a year. Combined with income tax plus residence tax (10%), the tax-saving effect is even greater.
Steps to start a blue-form return
  1. Submit the "application for approval of blue-form return" to the tax office (within 2 months of starting business, or by March 15 of that year)
  2. Set up accounting software (freee, Money Forward, Yayoi, etc.)
  3. Link your bank account and credit card to automatically import daily transactions
  4. At year-end, enter depreciation and inventory, and prepare the blue-form return financial statements
  5. File via e-Tax (e-filing is required to apply the ¥650,000 deduction)

Preparing the documents

Preparing your tax return starts with gathering documents from year-end into January. Use the checklist below and get them ready early.

① Documents related to the business

Blue-form return financial statements / income statement form

Output from accounting software. Blue-form = profit and loss statement + balance sheet. White-form = income statement form only.

Required
Books, receipts, and slips (keep for 7 years)

No need to submit, but keep them in case of a tax audit. Electronic data (scans) are also fine.

Required
Payment records (sent by clients)

Arrive from clients who withheld tax. No need to submit, but you must check them to enter the withheld tax amount on your return.

Check

② Documents related to deductions

Social insurance premium deduction certificate (National Pension)

Mailed by the Japan Pension Service every October to November. For National Health Insurance, check your municipality's payment history.

Required
Payment certificate for small business mutual aid, etc.

If you are enrolled in the Small Business Mutual Aid or iDeCo, it is sent around November.

If applicable
Life insurance premium deduction certificate

Arrives from each insurance company in October to November. Up to ¥40,000 deduction for each of the 3 categories: life, nursing-care medical, and personal pension.

If applicable
Medical expense receipts and medical expense notices

If you have medical expenses of over ¥100,000 a year (or over 5% of income). The health insurance association's notice lets you check them all at once.

If applicable
Furusato nozei receipt certificates

Receipts (donation receipt certificates) sent by each municipality. Needed if you do not use the one-stop exception.

If applicable
Special deduction certificate for housing loans, etc.

From the second year of the mortgage deduction onward, file it together with the year-end balance certificate that arrives from the tax office.

If applicable

③ Identity verification documents

My Number Card (when using e-Tax)

E-filing requires a My Number Card and a card reader (or a smartphone).

Required
Account information for direct debit

If you pay tax by account transfer, have your bank account number and financial institution code ready.

If applicable
Digital document management is recommended

Saving receipts as PDFs with your smartphone camera or a scanner saves you the trouble of searching for them at filing time. If you meet the requirements of the Electronic Books Preservation Act (resolution, time stamp, etc.), you no longer need to keep paper copies.

Filing steps (step by step)

Here are the steps to get through your tax return smoothly, along with a year-round schedule. The biggest tip is to avoid "panicking once the filing period arrives."

Year-round
STEP 1 | Daily bookkeeping and keeping receipts

Enter sales and expenses into accounting software (freee, Money Forward, etc.) as they occur. If you link your bank account and credit card, most entries are made automatically.

Check that receipts include the "date, amount, purchase details, and payee"
Separating private and business accounts and cards makes journaling easier
Cash payments are especially easy to forget, so make a habit of scanning and entering them on the spot
January
STEP 2 | Collecting deduction certificates and payment records

From year-end into January, deduction certificates for the National Pension, life insurance premium deduction certificates, payment records from clients, and so on arrive. As they come in, gather them into a single file right away.

Payment records are not mandatory to send (optional), so they may not arrive. Check with your clients
Confirm that your furusato nozei receipt certificates are all in hand
Jan–Feb
STEP 3 | Year-end adjustments (closing the books)

Close your books for the year and prepare the financial statements. If you use accounting software, do the following on the "year-end adjustment" screen.

Recording depreciation

Assets of ¥300,000 or more, such as PCs, machinery, and vehicles, are expensed each year using the straight-line or declining-balance method. Using the blue-form under-¥300,000 special rule lets you expense them in a lump sum.

Inventory count (for businesses with stock)

Check the value of inventory as of the end of December and record it as "closing inventory." Note that the more inventory you have, the smaller your expenses (cost of sales) become.

Adjusting accrued and prepaid expenses

Expenses paid in December but attributable to the following year (e.g., paying rent for January–March in December) are treated as "prepaid expenses."

Checking accounts receivable and payable

Accurately record accounts receivable billed but uncollected at year-end, and unpaid purchase costs.

Feb–Mar
STEP 4 | Preparing the return

Prepare your return using the National Tax Agency's "Tax Return Preparation Corner" (e-Tax) or your accounting software. Follow the on-screen instructions and it calculates automatically.

First page (Form A abolished → everyone uses the equivalent of Form B)

The main sheet where you enter the totals for income, income deductions, and tax.

Second page

Enter the details of each deduction (social insurance premiums, life insurance premiums, etc.).

Blue-form return financial statements (for a blue-form return)

The profit and loss statement (pages 1–2) and the balance sheet (pages 3–4). Double-entry bookkeeping requires the balance sheet too.

Enter any withheld tax in the "withheld tax amount" field to receive a refund
If you made estimated tax prepayments, enter them in the "estimated tax prepayment" field
3/15
STEP 5 | Filing (deadline: March 15)

There are three ways to file. e-Tax (e-filing) is the most recommended.

e-Tax (e-filing) ★ recommended
  • Can file 24 hours a day, 365 days a year
  • Completed with a My Number Card + smartphone
  • The blue-form special deduction becomes ¥650,000 (¥550,000 on paper)
  • Faster refunds (usually within 3 weeks)
  • Can omit attaching deduction certificates
By mail (sending documents to the tax office)
  • Postmark by March 15 is valid
  • Enclose the originals of deduction certificates, etc.
  • Always keep a copy of your return for yourself
Delivering to the tax office counter in person
  • Go early, as it tends to be crowded
  • You can file while checking at the filing consultation counter
  • Some offices open on Sundays during the period
Mar–Apr
STEP 6 | Confirming payment or refund
Payment (if there is tax due)
  • Pay by March 15
  • Direct debit (account transfer) is deducted in mid-April
  • Direct pay, convenience store, and credit card payment are also possible
Refund (if you overpaid)
  • With e-Tax, usually transferred within 3 weeks
  • Paper filing can take 1–2 months
  • Enter the destination account accurately on your return
Estimated tax prepayment (July, November): if the prior year's income tax was ¥150,000 or more, this system prepays the following year's tax. It is settled at the time of the tax return.

How to use e-Tax (e-filing)

e-Tax lets you complete your return using only a smartphone. Smartphone filing with a My Number Card is the simplest method.

Steps to file on a smartphone

1
Install the Mynaportal app

Available for both iOS and Android. Because it uses the My Number Card's NFC reading function, you need a compatible smartphone (almost all recent smartphones are compatible).

2
Link external services in Mynaportal

Set up automatic linking of deduction certificates (National Pension, private insurance, etc.). Linking in advance greatly reduces data entry.

3
Access the Tax Return Preparation Corner

Start from the National Tax Agency's site or Mynaportal's "tax return" menu. Select "use a smartphone."

4
Verify your identity with the My Number Card

Hold the card to your smartphone to read the IC chip, and enter the password for the user certificate electronic certificate (a 4-digit number).

5
Prepare and submit the return

Follow the on-screen instructions to enter income, expenses, and deductions. Linking the financial statement data prepared in accounting software (in XML format) lets you skip data entry. Finally, press the submit button and you're done.

Filing methodWhat you needBlue-form special deductionDifficulty
Smartphone (My Number Card) My Number Card, NFC-compatible smartphone ¥650,000 ★★☆
PC (My Number Card) My Number Card, IC card reader, PC ¥650,000 ★★★
PC (ID/password method) ID and password obtained in advance at the tax office ¥650,000 ★★☆
Paper (mail/counter) Printout, original deduction certificates ¥550,000 ★☆☆
Linking accounting software with e-Tax

Accounting software such as freee, Money Forward, and Yayoi has a function to send the financial statements you prepared directly to e-Tax. This saves you from separately entering data into the return preparation corner, so if you use accounting software, taking advantage of that function is the smoothest approach.

Easily missed income deductions

On a tax return, in addition to booking expenses, you can apply many income deductions. Missing a deduction means paying extra tax, so check the following carefully.

Social insurance premium deduction
Fully deductible

The full amount of National Pension and National Health Insurance premiums. Also deductible if you paid for family members together.

Small business mutual aid, etc. premium deduction
Fully deductible

The full amount of Small Business Mutual Aid and iDeCo contributions. The strongest tax-saving tool available to sole proprietors.

Medical expense deduction
Portion over ¥100,000

Deductible if annual medical expenses exceed ¥100,000 (or that amount when it exceeds 5% of income). Family members' expenses can be combined.

Life insurance premium deduction
Up to ¥120,000

Up to ¥40,000 each for the 3 types — life, nursing-care medical, and personal pension — for a total of up to ¥120,000.

Earthquake insurance premium deduction
Up to ¥50,000

The full amount of earthquake insurance premiums (cap of ¥50,000). Even renters qualify if their household goods insurance has an earthquake rider.

Donation deduction (furusato nozei)
Donation amount − ¥2,000

Sole proprietors cannot use the one-stop exception, so they need to receive the deduction on their tax return.

‍‍
Dependent deduction / spouse deduction
¥380,000–630,000

When you have dependents in the same household. If your spouse's income is ¥580,000 or less, the spouse deduction (¥380,000) applies.

Disability deduction / widow deduction
¥270,000–750,000

Applies when you or a dependent has a disability, or when you qualify as a single parent or widow(er).

Self-medication tax system
Portion over ¥12,000

The portion of OTC medicine (over-the-counter drug) purchases exceeding ¥12,000 (cap of ¥88,000). Chosen as an alternative to the medical expense deduction.

Example of making full use of deductions (a sole proprietor with ¥3.5 million business income and no employment)
Business income¥3,500,000
Blue-form special deduction (e-Tax)−¥650,000
Basic deduction−¥580,000
Social insurance premium deduction (National Pension + National Health Insurance)−¥580,000
Small Business Mutual Aid (¥30,000/month × 12 months)−¥360,000
iDeCo (¥20,000/month × 12 months)−¥240,000
Life insurance premium deduction−¥80,000
Taxable income¥1,010,000
Income tax (5%) + residence tax (10%), estimateabout ¥151,500
Without deductions, the tax would be about ¥420,000. Making full use of each deduction saves about ¥270,000.

Common mistakes and fixes

Here are the points where many people slip up on their tax return. Knowing them in advance helps you avoid trouble.

01
You missed the filing deadline (non-filing)
Problem

If you leave it unfiled, the additional tax for non-filing (5–20%) and delinquent tax (annual 2–14.6%) are added to the tax originally due.

Fix

File as soon as you notice (late return). If you file voluntarily, the additional tax is reduced to 5%. Once the tax office points it out, the additional tax increases.

02
There was an entry or calculation error (amended return / request for correction)
Problem

When you reported too little income (paid too little tax), or forgot to claim a deduction (paid too much tax).

Fix

If the tax increases, submit an "amended return." If the tax decreases (overpaid), submit a "request for correction" within 5 years of the filing deadline to receive a refund.

03
Missing or over-booked expenses
Problem

If you book expenses unrelated to the business, they may be disallowed in a tax audit and result in a penalty. Conversely, missing expenses means paying extra tax.

Fix

Only book expenses whose connection to the business you can clearly establish. For gray-area spending, note the "business purpose" on the receipt. For household-use apportionment, record a reasonable basis (area ratio, time ratio).

04
Forgot to enter the withheld tax amount on the return
Problem

If a client withheld tax (10.21% is deducted), you cannot receive a refund unless you enter that amount on your return.

Fix

Total the withheld tax from payment records or your accounting books, and enter it accurately in the "withheld tax amount" field on your return. Entering it refunds the tax you overpaid.

05
You never submitted the blue-form return notification
Problem

Even if you meant to file blue-form, without submitting the application for approval you are treated as a white-form filer and cannot receive the ¥650,000 deduction.

Fix

File this year's return as white-form, and to switch to blue-form from next year, submit the application for approval to the tax office by March 15. If you have just started your business, the deadline is within 2 months of starting.

06
Forgot to pay estimated tax prepayment
Problem

If the prior year's income tax was ¥150,000 or more, you are obligated to make "estimated tax prepayments" in July and November. Forgetting to pay incurs delinquent tax.

Fix

The tax office sends a "notice of estimated tax prepayment" in June, so don't miss it. If your income has dropped significantly, you can reduce it by submitting an "application to reduce estimated tax prepayment."

Sole proprietor's tax calendar (year-round schedule)
January

• Collect payment records and deduction certificates

• Start closing the books

February

• Start preparing the tax return

From 2/16, filing acceptance begins

March

3/15 tax return and payment deadline

• Deadline to apply for next year's blue-form return (3/15)

April

• Direct debit withdrawal (mid-April)

• Residence tax determination notice (May–June)

June

• Residence tax payment begins (from June)

• Estimated tax prepayment notice arrives

July

Estimated tax prepayment, 1st installment (by 7/31)

Oct–Nov

• Deduction certificates start to arrive

Estimated tax prepayment, 2nd installment (by 11/30)

December

• Deadline to submit the application for approval of blue-form return (for next year)

• Organize the year's receipts and books

Learn more with related columns and pages

FAQ

When is the tax return period?

As a rule, February 16 to March 15 of the following year. Payment is also due March 15 (mid-April for direct debit). A refund claim can be filed even before February 15, and you can go back up to 5 years.

Should I file blue-form or white-form?

If you have business income, the blue-form return is advantageous, with benefits such as a deduction of up to ¥650,000, loss carryover, and family employee salary. Blue-form requires prior approval (by March 15 of that year / within 2 months for a new business).

Should I file even at a loss?

With a blue-form return you can carry a net loss forward for 3 years, so filing even at a loss lets you offset it against future profits. Filing is also useful for the calculation of National Health Insurance premiums.

Sources and official information

This article is based on the following official information. Rules may be revised. Check the latest information on each official site.

* The content of this article is for informational purposes and is not tax or legal advice. For individual tax decisions, consult your local tax office or a licensed tax accountant (zeirishi).