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).

Tax Guide for Sole Proprietors

The tax-saving essentials that freelancers and the self-employed need, organized clearly.

From the blue-form return, claiming business expenses and consumption tax to social insurance, we explain how to make full use of your tax return to cut your tax burden wisely.

Blue-form special deduction

Save big with a deduction of up to ¥650,000. The key points on filing and bookkeeping.

Essential

Claiming and apportioning expenses

Book business-related costs correctly. We also explain the idea of household apportionment.

Tax saving

Small Enterprise Mutual Aid & iDeCo

The strongest combo of retirement planning and tax saving, with higher limits than for employees.

Retirement

Consumption tax & the invoice system

Judging your tax liability and the criteria for deciding on invoice registration.

Consumption tax

National Health Insurance & tax saving

Use the mechanism where lower income also means lower premiums.

Social insurance

The tax-return process

A summary of the annual schedule and the documents you need.

Filing

Blue-form special deduction

One of the largest deductions a sole proprietor can claim on a tax return is the blue-form special deduction. Simply by filing an application in advance and keeping your books by double-entry bookkeeping, you can subtract up to ¥650,000 from your business income. For details such as the requirements for ¥650,000, ¥550,000 and ¥100,000, loss carryforward and salaries for family employees, see Blue-form vs. white-form returns.

White-form return
No deduction (¥0)
Blue-form return
Simplified bookkeeping
¥100,000
Blue-form return
Double-entry (paper filing)
¥550,000
Blue-form return
Double-entry + e-Tax
¥650,000

Other benefits of the blue-form return

Net-loss carryforward

A loss in a year in the red can be carried forward for the next three years and deducted from income.

‍‍
Salary for blue-form family employees

Salaries paid to family members can be booked as expenses. The white-form return only allows a "deduction" capped at ¥500,000–¥860,000.

Special rule for small-value depreciable assets

Equipment costing under ¥300,000 can be expensed in full at once (up to ¥3,000,000 per year in total).
→ A special rule for depreciation

What to do when you start your business

Submit the "Application for Approval of Blue-Form Filing" to the tax office within 2 months of starting your business. Using accounting software (freee, Money Forward, etc.) handles double-entry bookkeeping almost automatically.

Formula
Business income = revenueexpensesblue-form special deduction (up to ¥650,000)

※ You then also subtract the ¥580,000 basic deduction, the social insurance premium deduction and others from business income before applying the tax rate.

Example: revenue ¥5,000,000, expenses ¥1,500,000, blue-form filed via e-Tax
Revenue¥5,000,000
Expenses− ¥1,500,000
Blue-form special deduction− ¥650,000
Business income¥2,850,000
Income difference vs. white-form return¥650,000
Tax-saving effect (rate 20% + residence tax 10%)approx. ¥195,000
Just switching from a white-form to a blue-form return saves close to ¥200,000 a year in this calculation.

Claiming and apportioning expenses

Spending related to your business can be subtracted from revenue as "necessary expenses." If you use your home as a workplace, household apportionment lets you book part of your rent and utilities as expenses.

What can be an expense (examples)
  • Purchases and materials
  • Outsourcing and subcontracting fees
  • Office rent and utilities
  • PC, smartphone and peripherals
  • Communication costs (internet, phone)
  • Books, seminars and study costs
  • Advertising costs
  • Entertainment and meeting costs with clients
  • Tax accountant and lawyer fees
  • Business casualty insurance premiums
What cannot be an expense (examples)
  • Living costs and food (non-business)
  • Income tax, residence tax and fines
  • Salaries to family (capped on the white-form return)
  • Private travel costs
  • Hobby goods (when not business-related)
  • Personal gym membership and lessons
  • National Pension and National Health Insurance (deducted separately as the social insurance premium deduction)

How household apportionment works

Work space
30%
Private
70%
Rent ¥100,000 ¥30,000/month as expense
Electricity ¥10,000 ¥3,000/month as expense
Communication ¥5,000 ¥1,500/month as expense
Household apportionment formula
Amount booked as expense = total spending × business-use ratio

※ Keep records so you can explain the basis for the business-use ratio (floor-area ratio, time ratio, etc.).

※ A reasonable ratio will be accepted even in a tax audit. Ratios that are too high risk being denied.

Example: one room of your home (25% of the total) used for work, monthly fixed costs ¥150,000
Rent¥100,000 × 25% = ¥25,000/month
Electricity, gas and water¥20,000 × 25% = ¥5,000/month
Communication (Wi-Fi, etc.)¥10,000 × 60% = ¥6,000/month
Other (insurance, etc.)¥20,000 × 25% = ¥5,000/month
Monthly amount booked as expense¥41,000
Annual amount booked as expense¥492,000
Booking about ¥490,000 a year in expenses saves about ¥147,000 at a 30% tax rate.

Small Enterprise Mutual Aid & iDeCo

Unlike employees, sole proprietors get no retirement allowance. Combining the Small Enterprise Mutual Aid and iDeCo lets you build up retirement assets while saving tax right now. A key feature is that the limits are higher than for employees, so the tax-saving effect is greater.

Small Enterprise Mutual AidiDeCo (individual type)
Monthly limit¥70,000¥68,000 (combined with the National Pension Fund)
Annual limit¥840,000¥816,000
Type of deductionSmall enterprise mutual aid premium deduction (full amount)Small enterprise mutual aid premium deduction (full amount)
Receiving benefitsOn closing the business or retirement (favorably treated as retirement income)From age 60 (retirement income or public pension deduction)
Early cancellationVoluntary cancellation risks a loss of principalIn principle, no withdrawal until age 60
Who it suitsThose who want to reliably save in place of a retirement allowanceThose who want to grow assets through investment

Annual benefit if you use both to the full

Small Enterprise Mutual Aid
¥70,000/month × 12 months = ¥840,000/year fully deductible
iDeCo
¥68,000/month × 12 months = ¥816,000/year fully deductible
Total
¥1,656,000 in income deductions per year!
Formula
Annual tax saving = (mutual aid premiums + iDeCo premiums) × (income tax rate + residence tax rate 10%)

※ The income tax rate is 5–45% depending on taxable income.

Example: taxable income ¥5,000,000, mutual aid ¥70,000 + iDeCo ¥30,000/month
Small Enterprise Mutual Aid (¥70,000/month × 12)¥840,000
iDeCo (¥30,000/month × 12)¥360,000
Total deduction¥1,200,000
Income tax saving (rate 20%)¥240,000
Residence tax saving (rate 10%)¥120,000
Total annual tax saving¥360,000
Save ¥360,000 a year while building retirement assets. Keep it up for 10 years and cumulative tax saving is about ¥3.6 million.

Consumption tax & the invoice system

Once your revenue two years prior exceeds ¥10 million, you must file and pay consumption tax. Also, under the invoice system (qualified invoice retention method) that started in October 2023, even tax-exempt businesses must decide whether to register.

What was your taxable sales
two years ago?
¥10 million or less
In principle, tax-exempt
No consumption tax filing or payment needed
※ But if you register for invoices, you become a taxable business
Over ¥10 million
Taxable business
Consumption tax filing and payment required
Choose the general or simplified method

General method vs. simplified method

General methodSimplified method
ConditionsNo restrictionsSales two years prior of ¥50 million or less
CalculationConsumption tax on sales − consumption tax on purchasesConsumption tax on sales × (1 − deemed purchase rate)
BookkeepingTrack the consumption tax you paid in detailJust tracking sales is fine
Who it suitsIndustries with many expenses and purchasesService businesses and others with few expenses
Key points of the invoice system (from October 2023)

For your counterparty to claim a purchase tax credit for consumption tax, they need a qualified invoice bearing a registration number. If you stay a tax-exempt business, your clients cannot claim the credit, so they may become reluctant to deal with you.

  • 20% special rule (until September 2026): If you become a taxable business upon invoice registration, you can reduce your tax to 20% of the consumption tax on sales (for individuals, through the return for 2026).
  • 30% special rule (2027–2028): After the 20% special rule ends, a measure setting sole proprietors' tax at 30% of the consumption tax on sales is planned to be created in the FY2026 reform (check the National Tax Agency for the latest).
  • Small-amount special rule: Purchases under ¥10,000 (tax included) qualify for a purchase tax credit without retaining an invoice (until September 2029; for businesses with sales of ¥100 million or less, etc.).
  • Transitional measures: Purchases from unregistered businesses are eligible for an 80% credit until September 2026 and a 50% credit until September 2029.

For how to decide on registration and choose a taxation method, see The invoice system and tax-exempt businesses.

Consumption tax formula (general method)
Tax payable = consumption tax on salesconsumption tax on purchases and expenses

※ For the simplified method: tax payable = consumption tax on sales × (1 − deemed purchase rate). The deemed purchase rate is 40–90% depending on the industry.

Example: annual sales ¥13.2 million (tax included), purchases and expenses ¥4.4 million (tax included)
Consumption tax on sales (¥13.2M incl. tax × 10/110)¥1,200,000
Consumption tax on purchases (¥4.4M incl. tax × 10/110)− ¥400,000
Consumption tax payable (general method)¥800,000
When purchases and expenses are low, the simplified method can be more advantageous. Estimate in advance before choosing.

National Health Insurance & tax saving

Premiums for the National Health Insurance that sole proprietors join are calculated based on the previous year's income. Because lower income means lower premiums, tax saving through booking expenses and various deductions directly cuts your premiums too.

Composition of the National Health Insurance premium (medical portion)
Income-based portion
(previous year's income − ¥530,000) × rate
The rate varies by municipality (guide: 8–11%)
Per-capita portion
A fixed amount per enrollee
(e.g. around ¥47,000/year)

Premium guide by income (Tokyo, single person)

Business incomeAnnual premium (approx.)Monthly equivalent
¥1 millionapprox. ¥100,000approx. ¥8,300
¥2 millionapprox. ¥190,000approx. ¥15,800
¥3 millionapprox. ¥280,000approx. ¥23,300
¥4 millionapprox. ¥370,000approx. ¥30,800
¥5 millionapprox. ¥460,000approx. ¥38,300
¥6 million or morecap approx. ¥860,000 (medical portion)capped

※ The total premium including the long-term care portion and support portion is higher than the above. It varies greatly by municipality.

National Health Insurance premiums are fully deductible as the social insurance premium deduction

National Health Insurance and National Pension premiums you pay can be fully deducted from income as the social insurance premium deduction. Be sure to claim them on your tax return. The National Pension is about ¥198,480/year (FY2024).

How premiums come down
National Health Insurance premium (income-based portion) = (business income − ¥530,000) × rate

※ Booking expenses correctly to lower your income directly cuts your premiums too.

Example: revenue ¥5 million, expenses increased by ¥1 million (rate 9%)
Business income before the expense increase¥4 million
Income-based portion ((¥4M − ¥430,000) × 9%)¥321,300/year
Business income after adding ¥1 million of expenses¥3 million
Income-based portion ((¥3M − ¥430,000) × 9%)¥231,300/year
Premium savings¥90,000/year
On top of saving income tax and residence tax, your premiums fall too, so the real boost to take-home pay is even larger.

The tax-return process

Sole proprietors must file a tax return each year between February 16 and March 15. Keeping your books throughout the year means you won't scramble during the filing period.

Jan–Dec
Day-to-day bookkeeping

Record sales and expenses as they occur. Keep receipts and slips (for 7 years).

Mid-January
Receiving payment records

Clients send payment records for amounts withheld at source (submission is optional, but you must check them).

Late Jan–early Feb
Closing the books and year-end adjustments

Reflect depreciation and inventory. Prepare the blue-form financial statements (or the statement of income and expenses).

Feb 16–Mar 15
Filing the tax return

File via e-Tax (online), at the tax office counter, or by mail.

Mar–Apr
Refund or payment

Any refund is transferred to your designated account. Payment is due by March 15 (mid-April for account-transfer payment).

Main documents needed for a tax return

Blue-form financial statements

Profit and loss statement, balance sheet (for double-entry bookkeeping)

My Number verification documents

My Number Card, or notification card + ID

Social insurance premium deduction certificate

Proof of National Pension and National Health Insurance paid

Mutual aid and iDeCo certificates

Small enterprise mutual aid premium payment certificate

Life insurance premium deduction certificate

Mailed by the insurer around November

Loan balance certificate

If you have the mortgage loan credit

Why e-Tax (electronic filing) is recommended

Filing via e-Tax applies the ¥650,000 blue-form special deduction (paper filing gives ¥550,000). With a My Number Card you can even file from your smartphone, and refunds come faster (usually within 3 weeks).

Learn more in related articles and pages

Blue-form vs. white-form returns

Requirements for the ¥650,000 deduction, loss carryforward, family salaries and application deadlines.

10 gray-zone expenses

Sorting out cases where it's hard to judge whether something can be an expense.

Invoices & tax-exempt businesses

Deciding on registration, plus the 20%/30% and small-amount special rules with the latest info.

The tax-saving effect of iDeCo

Premiums are fully deductible from income, and sole proprietors have higher limits.

Expense list (detailed guide)

Check the thinking on expenses by account category all in one place.

When to incorporate

Consider it as income rises. A guide to the break-even point of incorporating.

Small Enterprise Mutual Aid

A retirement-allowance system for sole proprietors where premiums are fully deductible from income.

Calculating National Health Insurance

The income-based and per-capita portions, the ¥1.09 million cap, and tips to reduce it.

The basics of accounts and journal entries

A list of common accounts and practical rules for when you're unsure.

The Electronic Books Preservation Act

Storing electronic transaction data, mandatory from 2024. So what do you actually need to do?

Individual enterprise tax

A prefectural tax on income over ¥2.9 million. Rates by industry and the August payment.

Estimated tax prepayment

A prepayment of income tax notified in June. Reduction requests are due by July 15.

Salary for blue-form family employees

Booking family salaries as expenses: requirements, filing and setting a reasonable amount.

FAQ

What do I file first when I start a business?

Submit the "notification of business start" to the tax office, and if you want to file blue-form, the "Application for Approval of Blue-Form Filing." The application is due within 2 months of starting your business (or by March 15 of that year if you are already in business).

How do I get the ¥650,000 blue-form deduction?

Keep your books by double-entry bookkeeping, submit the balance sheet and profit and loss statement on time, and either file electronically via e-Tax or keep qualifying electronic books; then it becomes ¥650,000 (¥550,000 if you don't go electronic).

Should I register for invoices even with sales of ¥10 million or less?

If your clients are mainly taxable businesses, consider registering; if they are mainly general consumers, the impact is often small. Registering makes you a taxable business with a duty to pay consumption tax. Also check burden-easing measures such as the 20% special rule (until September 2026).

How far are expenses allowed?

Expenses are the spending necessary to earn your business revenue. For a combined home and office, apportion rent, utilities and communication costs by the business-use ratio. Keep records so you can explain the basis for the ratio.

Sources / official information

This article is based on the official information below. Rules may be revised; please check each official site for the latest details.

※ This article is for general information only and is not tax or legal advice. For individual tax matters, consult your local tax office or a licensed tax accountant (zeirishi).