This is a translation of the Japanese original. The Japanese version is authoritative; figures follow Japanese tax law.
A sole proprietor in Japan may or may not use a trade name (屋号, yago). If you do use one, no registration is needed: you simply write it in the "trade name" box on the notification of commencement of business (開業届). However, you cannot use words that make people think you are a company, such as "kabushiki kaisha" (株式会社, joint-stock company) or "godo kaisha" (合同会社, limited liability company) (Article 7 of the Companies Act)[e-Gov, Companies Act art. 7]. You can also register the name to keep it, but registering a commercial name (商号, shogo) as an individual is optional (Article 11(2) of the Commercial Code)[e-Gov, Commercial Code art. 11]. And one more thing: the deadline for the notification of commencement of business is no longer "within one month of starting". From 1 January 2026 it is "by the filing deadline for that year's income tax return", so a business started in 2026 has until 15 March 2027[NTA, A1-5]. This article sorts out how to choose a name, where to write it, and how to change it, using the original texts.
The short answer: what you have to do, and what you do not
| Action | Required or optional | Where and what |
|---|---|---|
| Decide on a trade name | Optional. Your own name is fine | — |
| Write it in the "trade name" box of the notification | The form merely has a box. You can file without filling it in | The tax office for your place of tax payment (notification of commencement or discontinuance of business) |
| File the notification of commencement itself | Required (Article 229 of the Income Tax Act) | Same office, by the filing deadline for that year's tax return |
| Register the trade name as a commercial name | Optional (Article 11(2) of the Commercial Code) | Legal Affairs Bureau. Registration and licence tax applies |
| Show the trade name on the invoice public register | Optional | "Application for publication (or change) of published matters of a qualified invoice issuer" |
| Open a bank account in the trade name | Optional | Each bank decides. There is no nationwide rule |
Sources: National Tax Agency, "A1-5 Notification of commencement or discontinuance of a sole proprietorship"[NTA]; Companies Act art. 7 and Commercial Code art. 11[e-Gov]. We could not find a National Tax Agency text stating in so many words that the trade name box is "optional". What the notification must contain is fixed by Article 229 of the Income Tax Act and its enforcement regulation, and the filing stands even without a trade name.
A trade name is the name you tell the tax office you trade under. It creates no exclusive legal right. Names are protected by commercial name registration or by trademarks, which are separate systems.
There are only three places you write the trade name
- The "trade name" box on the notification of commencement of business. The form has a trade name box with a reading in kana[NTA, form]. It goes to the head of the tax office with jurisdiction over your place of tax payment. You can file through e-Tax or on paper.
- The financial statements or the statement of income and expenses. The header of the blue-return financial statements has a box for "type of business / trade name"[NTA, form].
- Invoices and receipts. It can also be the name on a qualified invoice (see below).
It used to be "within one month of the day the business was started". The fiscal 2025 reform amended Article 229 of the Income Tax Act, and from 1 January 2026 it is "by the filing deadline for the income tax of the year in which that fact occurred"[e-Gov, Income Tax Act art. 229]. A business started during 2026 therefore has until 15 March 2027.
The application for approval of blue-return filing has its own deadline: within two months of starting if you start on or after 16 January, or 15 March of that year if you start by 15 January[NTA, how to fill in]. The full picture of what to file is in our guide to starting a sole proprietorship.
Names you cannot use: nothing that suggests a company
Article 7 of the Companies Act puts it like this: "A person who is not a company shall not use in its name or commercial name any characters that are likely to be mistaken for a company."[e-Gov, Companies Act art. 7]
Companies, for their part, must include in their commercial name the words for their type: "kabushiki kaisha", "gomei kaisha" (general partnership company), "goshi kaisha" (limited partnership company) or "godo kaisha" (Article 6(2) of the Companies Act)[e-Gov, Companies Act art. 6]. Turn that around and an individual is not allowed to put those words in a trade name.
Trade names you can use
- "X kobo" (workshop), "X shoten" (store), "X komuten" (builders)
- "X Design Office", "X Planning"
- Your own name as it is (no trade name is fine too)
Trade names to avoid
- Kabushiki kaisha X / X kabushiki kaisha
- X godo kaisha / X gomei kaisha / X goshi kaisha
- Anything likely to be mistaken for a company
- Words reserved by industry law, such as bank or insurance
The other issue is trademarks. Writing a trade name on the notification does not guarantee you the right to use that name. A trade name identical to a well-known product name can raise trademark problems. It is safer to check in advance whether the same name is already in use.
"Trade name" and "commercial name" are different: register if you want to keep the name
Article 11 of the Commercial Code provides, for merchants other than companies, that "a merchant may register its commercial name"[e-Gov, Commercial Code art. 11(2)]. "May" means it is optional. A company necessarily has its commercial name registered when it is incorporated; an individual is under no such duty.
| Trade name (a tax filing) | Commercial name (a registration) | |
|---|---|---|
| Procedure | Write it in the box on the notification | Apply to the Legal Affairs Bureau |
| Cost | Only filing the notification | Registration and licence tax applies |
| Protection of the name | None | Blocks registration of the same name at the same address |
Source: Legal Affairs Bureau, "Commercial and corporate registration"[Legal Affairs Bureau]. Check the amount of registration and licence tax and the documents required in the bureau's guidance. You can search existing registrations of the same commercial name through the Ministry of Justice's online registration information search service[Ministry of Justice].
Most sole proprietors get along fine without registering. It is a step to consider when you will use a sign for many years, or when a similar name exists in your line of business. For a company, the commercial name appears in the incorporation registration. Compare the costs in the cost of setting up a company.
Changing your trade name: three places to deal with
There is no dedicated procedure in the National Tax Agency's guidance for notifying a change of trade name alone. The notification covers "starting a business", "opening, adding, relocating or closing an office or place of business" and "discontinuing a business"; a change of trade name is not listed[NTA, A1-5]. In practice there are three things to do.
| Who | What to do | Deadline |
|---|---|---|
| Tax office (income tax) | Write the new trade name in the trade name box of the tax return and the financial statements. If you receive a pre-printed form, correct it | By that year's tax return |
| Tax office (qualified invoices) | To publish or correct the trade name on the public register, file the "Application for publication (or change) of published matters" | None set (whenever you want the change) |
| Prefecture (enterprise tax on individuals) | "Notification of commencement (or discontinuance) of business". Tokyo requires it within 10 days of the change (15 days for a start) | Set by each local government |
Sources: National Tax Agency, "Guide to the income tax return" (correcting pre-printed entries)[NTA]; Tokyo Metropolitan Bureau of Taxation, "Enterprise tax on individuals"[Tokyo Metropolitan Bureau of Taxation]. Enterprise tax on individuals is a prefectural tax, so deadlines and forms differ by prefecture.
You also have to update clients, invoice templates, the name on your bank account and your business cards. The paperwork is light, but the tidying around it is heavy. That is why people say it is easier to settle on a trade name at the start.
You can add the trade name to the invoice public register
Once you are registered, your name, registration number and date of registration appear on the National Tax Agency's public register[NTA, public register]. For a sole proprietor the statutory published matters stop at the personal name; the trade name is not included. What you can add by application is your "main trade name" and "the location of your main office"[NTA, invoice Q&A, Q19].
A National Tax Agency leaflet likewise explains that you can publish your trade name by filing the "Application for publication (or change) of published matters"[NTA, leaflet]. If you do not publish it, a client searching by your registration number sees only your personal name. That does not match the shop name on the invoice and makes the issuer hard to identify, so publishing is the considerate choice if you invoice under a trade name.
Can an invoice or receipt show only the trade name?
The answer is yes. A qualified invoice must contain six items, the first of which is "the name and registration number of the qualified invoice issuer"[NTA, invoice Q&A]. Either your personal name or your trade name satisfies it.
- 1. The issuer's name and registration number
- 2. The date of the transaction 3. What it was for (and a note if the reduced rate applies)
- 4. The total for each tax rate and the rate applied
- 5. The consumption tax for each rate 6. The name of the business receiving it
What identifies you to the other side is the registration number. The trade name is how you introduce yourself; the number is the ID card. If you write only the trade name, publishing it on the register makes the match easier to confirm. On how to write one, see the six items on a qualified invoice; for work subject to withholding, see how a freelancer writes an invoice.
Bank accounts in a trade name: there is no nationwide rule
You often read that "a copy of the notification of commencement is needed for an account in a trade name". But there is no National Tax Agency or local government document setting out the requirements for opening such an account. The conditions are set by each bank, and the documents differ. If you plan to open one, ask the bank directly. Keeping a copy of the notification (a carbon copy on paper, or the receipt notice from e-Tax) is worth doing anyway.
That said, having one account used only for the business matters more than whether the name on it is a trade name.
Choosing in practice: check three things and stop
- Does it have one obvious reading? You will say the trade name over the phone, and it becomes the name on bank transfers. A name that can be read two ways needs explaining every time.
- Does it say what you do? Something like "X komuten" (builders) carries the line of business on a business card and in search results. The guidance for the "occupation" box on the notification also asks for something specific, such as "retail of Western confectionery"[NTA, blue-return approval application]. The same thinking works for a trade name.
- Is it already taken? Make sure there are no words that could be mistaken for a company, and search for registrations of the same commercial name through the Ministry of Justice's online registration information search service[Ministry of Justice].
Clear those three and you are done. A trade name says nothing about the substance of the business. Filing the notification and keeping your books does more for your take-home pay.
Frequently asked questions
I have not decided on a trade name. Can I leave the box on the notification empty?
You can file with it empty. What the notification must contain is fixed by Article 229 of the Income Tax Act and its enforcement regulation, and nothing is missing without a trade name. If you start using one later, writing it in the trade name box of your tax return and financial statements is enough.
I am late filing the notification of commencement. Have I missed the deadline?
From 1 January 2026 the deadline is "by the filing deadline for the income tax of the year in which that fact occurred". A business started in 2026 has until 15 March 2027, so you are probably still in time. Note that the application for approval of blue-return filing has its own deadline (within two months if you start on or after 16 January).
Can I use "X Company" as a trade name?
What Article 7 of the Companies Act forbids is "characters that are likely to be mistaken for a company". Type names such as "kabushiki kaisha" or "godo kaisha" cannot be used. Other words are judged case by case, so ask the Legal Affairs Bureau or the tax office if you are unsure.
If I change my trade name, do I have to file a change notification with the tax office?
There is no dedicated procedure. Putting the new trade name in the trade name box of the tax return and the financial statements is enough. If your trade name is published on the invoice register you also file the "Application for publication (or change) of published matters", and if you have filed for enterprise tax on individuals you notify the prefectural tax office as well.
Reference links (sources)
- NTA, A1-5 Notification of commencement or discontinuance of a sole proprietorship — when and where to file
- NTA, notification of commencement or discontinuance of a sole proprietorship — form (the trade name box) / how to fill it in (the deadline)
- e-Gov law search — Companies Act arts. 7 and 6(2) / Commercial Code art. 11(2) / Income Tax Act art. 229
- NTA, To sole proprietors who show a trade name on invoices and receipts — publishing the trade name by application
- NTA, Q&A on the qualified invoice system — publication (published matters and the "main trade name") / required entries (the six items)
- Legal Affairs Bureau, Commercial and corporate registration / Ministry of Justice, online registration information search service — where to register and how to search names
- Tokyo Metropolitan Bureau of Taxation, Enterprise tax on individuals — within 10 days of a change, 15 days for a start
Note: we could not find primary source material setting out the requirements for opening a bank account in a trade name (each bank decides them). Nor is there National Tax Agency wording stating that the trade name box is "optional", so this article goes no further than "the filing stands even if you leave it blank".
