Definition
You registered your business under your family name, and ever since, every quotation goes out with "Marie Delcourt" at the top of the page.
The day you need a business card, a website and an email signature, that name says nothing about what you sell.
So you pick "Atelier Vela", you put it everywhere, and the question follows immediately: is that name worth anything, and does it have to be declared somewhere?
The trading name, nom commercial in French, is the name under which your business faces the public: the website, the business cards, the email signature, the letterhead on your invoices.
It is a name in use, not a legal identity. Your Sole proprietorship has no company name, unlike a company: it carries your first name and family name.
The trading name sits on top of that, like a label stuck on a file whose own title never changes.
What it does not change: the calculation, the invoice, the number
Marie collects €40,000 in 2026 in a non-regulated liberal activity, taxed under the BNC category (bénéfices non commerciaux, non-commercial profits) and attached to the general scheme, not to the Cipav fund of the regulated liberal professions, which applies a different rate.
Her Social contributions are calculated on the revenue collected, at a rate of 25.6% in 2026, so €10,240.
On top of that comes the vocational training contribution, 0.2% in 2026 for the liberal professions and owed as soon as revenue was declared in the previous calendar year, so €80: €10,320 paid to URSSAF for the year.
On the tax side, she reports the €40,000 she collected on the household income tax return, and it is the tax administration that then applies the 34% flat-rate allowance set for BNC income in 2026, leaving €26,400 taxable.
"Atelier Vela" plays no part in either line: the rates follow the nature of the activity, never the name given to it.
The same logic applies to invoices.
The trading name may fill the whole letterhead, it replaces nothing: the Mandatory invoice details cover, among other things, your first name and family name, your SIREN number and, since the 2022 reform, the words "EI" or "entrepreneur individuel" (sole trader) placed next to your name.
As long as you fall under the VAT basic exemption, an exemption notice is added, the most common wording until 31 December 2026 being "TVA non applicable, article 293 B du CGI", two others being accepted by the tax doctrine. From 1 January 2027 it becomes "TVA non applicable, article L. 233-3 du CIBS".
A client who wants to check that you exist searches for your SIREN, not for your trading name.
Declaring a trading name does not protect it. The National business register records the name you entered, it does not reserve it: two businesses can carry the same name without the register objecting, and nobody checks on your behalf that it was free.
If that name was filed as a trademark before you, its owner can stop you from using it, even after years of trading and a client base built on it.
That check belongs before the business cards are printed, not after.
Trading name, shop sign and trademark are three different things
The trading name identifies the business, the enseigne (shop sign) identifies the place where it operates: a baker can invoice as "Delcourt et fille" and display "Le Fournil de la place" above the window.
A trademark identifies neither: it is an industrial property title, filed with the INPI (the French industrial property office) for specific goods and services, over a given territory, valid for a period set by the intellectual property code and renewable.
Only filing a trademark gives you the right to stop someone else from using the name.
A trading name used publicly can create an earlier right against a later filing, but it has to be proven piece by piece, and its reach stops where the name is genuinely known.
A trademark is proven with a certificate.
Two other things are regularly confused with the trading name: the company name, which exists only in companies and which a micro-entrepreneur therefore does not have, and the domain name, whose registration creates no right over the name itself.
Choosing a name, declaring it, changing it
Three checks before growing attached to a name: the INPI trademark database, the Annuaire des entreprises (the official business directory) to see who already uses it, and the availability of the domain name.
Then two prohibitions: wordings reserved for companies, such as SARL or SAS, which a sole trader cannot display, and any name suggesting a qualification, an official approval or a size you do not have.
The declaration is made at the One-stop shop, either when you register or later through a modification filing.
The name then appears on your SIRENE status notice and in the business directory, which reassures the bank or the client who could find nothing under it.
Changing your mind does not cost you your number: the SIREN stays the same, only the display changes.
What remains are the contracts, the website, the platforms and the client accounts, to be updated one by one, and that is the real cost of a name change.
Frequently asked questions
Am I required to declare a trading name?
No, it is optional: without one, your business simply operates under your first name and family name, which is perfectly valid.
Declaring it at the one-stop shop puts it on the public registers and on your status notice, which makes client checks and the opening of a business bank account easier.
Can I invoice under my trading name alone?
No. It may appear on the letterhead, but the invoice must carry your first name and family name, the words "EI" or "entrepreneur individuel" and your SIREN number.
An invoice showing only the trading name is incomplete, and a client trying to verify that you exist will find nothing under that name.
Can two micro-entrepreneurs hold the same trading name?
Nothing prevents it at the declaration stage, since the register does not check whether the name is available.
The conflict is settled afterwards on trademark and unfair competition grounds, and the holder of a trademark filed with the INPI usually prevails.
The other business only stands a chance if it can prove, piece by piece, that it was already using the name publicly before the filing.
Can I run two activities under two trading names?
Yes, nothing forces you to present two trades under a single label.
You still hold one single SIREN number, your ceilings are assessed on everything you collect together, and contributions are calculated by nature of activity: the name on display changes neither of those.