Definition
First job delivered, invoice sent, then silence. Three weeks later, an email from the client's accounts department: invoice rejected, please reissue.
No amount is disputed, and neither is the work. What blocks it is three lines missing from the header, and the payment has just slipped by a full cycle.
Mandatory invoice details are the list of information every invoice must carry to be valid.
They are not commercial custom, nor a software default: they come from article L441-9 of the code de commerce (the French commercial code) for business-to-business dealings, and from article 242 nonies A of annexe II to the code général des impôts (the tax code) on the tax side.
The official list is published by Service Public Entreprendre, which last checked it on 11 August 2026. These details apply whoever the customer is: a company, a consumer or a public body.
A micro-entrepreneur's Invoice escapes none of them.
The regime lightens the bookkeeping, not the invoicing rules: your invoice must say what a fifty-person company's invoice says, with only two differences, the identity you state on it and the VAT line that does not exist.
The list, block by block
A compliant invoice answers five questions, and each question matches one block of the document.
- Who is writing? Your first name and surname, preceded or followed by the wording "EI" or "entrepreneur individuel" (sole trader), your registered address and your SIREN number. The SIRET number entry explains why clients tend to ask for the fourteen digits of the establishment instead.
- Writing to whom? The customer's name, their address when they are a consumer, the billing address if it differs, and the purchase order number whenever they issued one.
- When? The issue date, the date of the sale or of completion of the service, and a unique number drawn from an unbroken chronological sequence, whose rules live in Invoice numbering.
- What? A precise description of each product or service, the quantity, the unit price excluding VAT, any discount acquired at the date of the transaction, and the total sum payable.
- Paid when, and if not? The date on which payment falls due, the terms of any early-settlement discount, the rate of Late payment penalties, and a reference to the fixed recovery fee, which only a business customer owes and whose amount is set by decree.
Specific wordings are added on top, depending on your situation.
The Article 293 B notice applies for as long as you fall under the VAT exemption scheme, tax doctrine admitting several wordings for it rather than a single one.
The reverse-charge wording applies when the customer accounts for the tax.
Last come the references of your professional insurance policy for a craft activity, and the duration of the legal guarantee of conformity on certain goods sold to a consumer.
A €3,500 invoice, line by line
Camille rebuilds the website of a consulting firm for €3,500. Unregulated liberal activity taxed as BNC (non-commercial profits), under the VAT exemption scheme.
Her invoice fits on one page.
| Block | What she writes |
|---|---|
| Issuer | Camille Roux, EI, registered address in Nantes, followed by her SIREN number |
| Number and dates | Invoice 2026-014, issued 18 December 2026, work completed 15 December 2026 |
| Service | Website rebuild, fixed fee, €3,500 excluding VAT |
| VAT status | "TVA non applicable, article 293 B du CGI" |
| Settlement | €3,500 payable, due date and penalty rate stated |
No tax line, therefore no separate VAT-inclusive total: under the exemption, the net total is exactly what the client pays. What remains is the question of what the invoice leaves behind.
The €3,500 is turnover, not income.
In 2026, social contributions on an unregulated BNC activity attached to the régime général, and not to the Cipav, come to 25.6% of the amount collected, that is €896.
The Cipav is the fund for regulated liberal professions.
On top comes the vocational training contribution of 0.2% owed by the liberal professions, due once revenue was declared in the previous calendar year, that is €7.
So €903 goes to the URSSAF, and that 25.6% rate covers neither that contribution, nor the CFE (the local business tax), nor income tax, each of which is calculated separately.
The issue date dates the invoice, not the receipt.
Issued on 18 December 2026 and paid on 9 January 2027, Camille's invoice falls into the 2027 turnover: in a micro-enterprise it is the cash received that attaches a sum to a year, never the invoice.
Anyone declaring invoices issued gets the year wrong twice, in December and again in January.
The line "Dispensé d'immatriculation au registre du commerce et des sociétés et au répertoire des métiers" (exempt from registration with the commercial and trades registers) still sits on thousands of invoice templates, and it describes a situation that no longer exists.
Since 1 January 2023 the registre national des entreprises registers every self-employed activity, liberal professions included, and the trades register disappeared at the same moment.
The expensive part is not the obsolete line, it is the one it displaces: since the 2022 reform, the commercial code requires the wording "EI" or "entrepreneur individuel" next to your first name and surname.
A template borrowed from a colleague or downloaded from a blog almost always carries the first and never the second.
"Micro-enterprise" belongs nowhere on an invoice
This is the most common confusion on this ground, and it rests on a real ambiguity: the micro-enterprise is not a legal form, it is a tax and social regime sitting on top of a Sole proprietorship.
An invoice, for its part, identifies a legal person.
Nothing obliges you to write "micro-entrepreneur" or "auto-entrepreneur" on your invoices, and those words do not replace the "EI" wording, the only one the commercial code demands in that spot.
Your Trading name, for its part, is perfectly free to take up the whole letterhead. It must be added to your first name and surname rather than replacing them.
An invoice carrying nothing but your brand name is incomplete, and a client trying to check that you exist finds nothing under that name.
The second confusion sits between mandatory invoice details and terms and conditions of sale. The first are pieces of information carried by each invoice.
The second form a contractual document, handed over before the order, where your payment terms, cancellation conditions and refund policy live.
An invoice pointing to terms that were never communicated binds the client to nothing, and impeccable terms do not make an incomplete invoice compliant.
Frequently asked questions
What is the risk when a detail is missing?
The invoice is still payable: a client cannot refuse to pay on the sole ground that a detail is missing.
The omission is, however, a breach punishable by an administrative fine provided for in the commercial code and imposed by the consumer protection authority, its amount depending on the nature of the failure.
The everyday risk is more mundane: an accounts department that rejects the document, and payment pushed back by a full cycle.
Do I have to invoice a private customer?
Between professionals, an invoice is mandatory for every sale and every service.
With a consumer, it becomes mandatory above an amount set by ministerial order, and in every case as soon as the customer asks for one.
Below that, a receipt is enough, but nothing stops you issuing invoices systematically: it is the document that supports the entry in your income ledger, and the one an audit will ask you for.
Is a PDF or a handwritten invoice valid?
Yes, today: the law requires a written document carrying certain details, not a particular format, as the official page on invoicing rules confirms. That will not last.
The Electronic invoicing reform imposes a structured format sent through an approved platform, on a staggered timetable that reaches micro-enterprises last, and it adds new mandatory details, among them the SIREN number of a business customer and the nature of the transactions invoiced.
Does my invoice change after 1 January 2027?
On at least one point. Until 31 December 2026, the wording to use under the exemption remains "TVA non applicable, article 293 B du CGI".
From 1 January 2027, VAT rules move into a new code and it becomes "TVA non applicable, article L. 233-3 du CIBS". The old one remains accepted until 30 June 2028.
No other change is confirmed to date. This page is up to date as of 5 September 2026 and will be revised when the finance act is published.
These particulars apply to the invoice. For the quotation, which has its own, Compliant quotation carries them for you and flags the ones still missing.