If you invoice French businesses, or build the software that does, the list of mandatory mentions matters: a missing mention can be fined, and the e-invoicing reform adds new ones. Most of them are about identity: who sells, who buys, and their numbers. This guide lists the mentions service-public.fr gives for invoices between professionals, highlights the company data each one needs, and explains how to get that data right.
Every rule below comes from service-public.fr (page on invoice mentions checked on 11 August 2026; page on companies' commercial documents checked on 8 December 2025), read on 10 October 2026.
What you'll learn
- The mandatory mentions on an invoice between professionals
- The mentions that depend on company data, and where that data comes from
- The new mentions added by the e-invoicing reform, and when
- The fines for a missing mention
- How to keep customer data clean enough for invoicing
The mandatory mentions
According to service-public.fr, an invoice between professionals must show, among other things:
About the seller
- Its name (the legal name, for a company) and address.
- Its SIREN number.
- For a company: its legal form (EURL, SARL, SA, SNC, SAS…) and the amount of its share capital.
- Its intra-community VAT number.
About the buyer
- Its name (company name, or full name for an individual) and address.
- Its VAT number, if it's a business liable to VAT.
About the invoice
- The date of issue, and a unique number from a continuous sequence.
- The date of the sale or service.
- The purchase order number, if there is one.
About the amounts
- The description of each product or service, with quantities and unit prices excluding tax.
- The VAT rate, or the exemption mention.
- Totals excluding and including tax.
- The payment due date, late payment penalties, and the €40 flat fee for recovery costs.
Service-public.fr notes an exception: for invoices under €150 excluding tax, the VAT numbers aren't required.
The mentions that depend on company data
Half of the list above is about identity, and that's where errors creep in:
| Mention | Comes from | Common error |
|---|---|---|
| Seller's legal name, form, capital | Your own register entry | Brand used instead of legal name |
| Seller's SIREN and VAT number | Your own register entry | Typo, old number after a restructuring |
| Buyer's name and address | Your customer | Trading name, old address |
| Buyer's VAT number | Your customer | Missing, mistyped, invalid |
| Buyer's SIREN (from the reform) | Your customer | Missing, wrong company in a group |
Your own data is easy: check it once against the register. Your customers' data is the hard part, because it's typed in by many people over many years. See how to find a company's SIREN or SIRET.
What the e-invoicing reform adds
According to service-public.fr, the e-invoicing reform adds new mandatory mentions:
- the customer's SIREN;
- the delivery address, if it differs from the customer's address;
- the nature of the operations (goods, services or both);
- the mention of the option to pay VAT on debits, if applicable.
Service-public.fr gives the dates: 1 September 2026 for large companies and mid-sized companies (ETI), and 1 September 2027 for small and medium companies and micro-enterprises.
The customer's SIREN becomes a mandatory field on every invoice. If your customer file holds names but not SIRENs, that's the gap to close first. See French e-invoicing and your customers' SIREN.
What happens if a mention is missing
According to service-public.fr's page on commercial documents, a missing mention can be fined up to €15 per missing mention, capped at a quarter of the invoice amount. The real cost is often elsewhere: an invoice rejected by a customer's accounts payable team, a payment delayed, a VAT deduction questioned.
For software teams: fields to add or check
If you build or configure billing software for French customers, these are the customer fields the rules above depend on:
- Legal name (separate from any display or brand name).
- SIREN, validated on entry, required for French business customers.
- VAT number, validated, and checked with VIES for intra-EU customers.
- Billing address, and a delivery address field when it differs.
- Nature of operations (goods, services or both) at invoice level.
- A check date for the identity fields, so you know when they were last confirmed.
Seller fields (your own legal name, form, capital, SIREN, VAT number) usually live in settings: check them once against your own register entry.
Keeping customer data clean enough for invoicing
- Ask for the SIREN and VAT number at onboarding, on the account-opening form, and make them required for business customers.
- Validate the format on entry. The SIREN's ninth digit is a Luhn check digit, according to INSEE; the French VAT key is computed from the SIREN. See SIREN, SIRET and VAT formats.
- Check the number belongs to the customer. Look the SIREN up: same legal name, same address, active status.
- Check foreign VAT numbers with VIES. See checking a VAT number with VIES.
- Use the legal name, not the brand, on the invoice.
- Re-check before the reform dates that apply to you, and when a customer moves or changes name.
Fuentio's API will return, for a SIREN or VAT number, the legal name, legal form, registered office and status with its date, with the source and the check date. It isn't open yet: join the waitlist below to hear the day it opens.
See what we cover in France and Spain.
Limits. The list of mentions summarises service-public.fr (invoice mentions, page checked on 11 August 2026; commercial documents, page checked on 8 December 2025), read on 10 October 2026; sector rules can add mentions. The reform dates may change: check service-public.fr and impots.gouv.fr. Fuentio doesn't issue invoices and doesn't make anyone compliant. Not legal or tax advice.
Frequently asked questions
Is the SIREN mandatory on a French invoice?
Yes, the seller's SIREN. With the e-invoicing reform, the customer's SIREN becomes mandatory too: from 1 September 2026 for large companies and ETIs, and from 1 September 2027 for SMEs and micro-enterprises, according to service-public.fr.
Must the buyer's VAT number appear on the invoice?
Yes, if the buyer is a business liable to VAT, except for invoices under €150 excluding tax.
What's the fine for a missing mention?
Up to €15 per missing mention, capped at a quarter of the invoice amount, according to service-public.fr.
Should I use the brand or the legal name?
The legal name, as registered. The brand can appear too, but it doesn't replace it.
Sources
- Service-public.fr, mandatory invoice mentions (page checked on 11 August 2026): entreprendre.service-public.gouv.fr
- Service-public.fr, a company's commercial documents (page checked on 8 December 2025): entreprendre.service-public.gouv.fr
- INSEE, definition of the SIREN number: insee.fr