France e-invoicing 2026: why your customers' SIREN becomes mandatory

What changes from 1 September 2026

The French e-invoicing reform applies in stages. Since 1 September 2026, every company, whatever its size and legal form, must be able to receive electronic invoices through an accredited platform. Large companies and mid-sized companies (ETI) must also issue invoices in this format. Small and medium businesses (PME) and micro-businesses follow no later than 1 September 2027.

The obligation covers transactions between VAT-registered businesses established in France. Sales to consumers and transactions with customers established abroad do not produce an e-invoice: their data is sent to the tax authority as e-reporting. A simple PDF sent by e-mail is not an electronic invoice under the reform: the invoice must be issued in a structured format and go through an accredited platform.

The timeline and scope are detailed in the tax authority's FAQ (in French) and on the page “From when am I affected by the reform?” of impots.gouv.fr.

The four new mandatory mentions

The usual mentions required by the Commercial Code and the General Tax Code do not change: seller identity, date, invoice number, description, prices, VAT rate and amount, and so on. Decree no. 2022-1299 of 7 October 2022 adds four, mandatory from 1 September 2026:

• the customer's SIREN;
• the category of the transaction: delivery of goods, provision of services, or both when the invoice covers independent deliveries and services;
• the option to pay VAT on debits, where applicable;
• the delivery address of the goods, if it differs from the billing address.

The transaction category and the VAT-on-debits option are set once in your invoicing software, and the delivery address comes from the order. The customer's SIREN, on the other hand, depends on the quality of each customer record. It is the mention that takes the most work, especially in a file built up over the years from company names.

Why the customer's SIREN becomes central

The SIREN identifies the company itself, the legal unit, however many establishments it has. It plays three roles in the reform:

• Identifying the customer on the invoice. The trading name is not enough: several companies often share the same name, and one brand can cover different companies.
• Addressing the invoice. Each company designates the accredited platform or platforms on which it receives its invoices, in a directory of recipients run by the tax authority and made available to the platforms. To find the right platform, the sender relies on the customer's identification: its SIREN and, where relevant, the SIRET of the receiving establishment.
• Reporting data to the tax authority. The invoicing data transmitted includes the supplier's SIREN and the customer's.

If you hesitate between SIREN and SIRET for a customer with several sites, the article SIREN vs SIRET vs NIC: what is the difference? explains which to use.

What a wrong SIREN causes

The practical starter guide published by the tax authority distinguishes two situations:

• Rejection by a platform: format error, missing or inconsistent mandatory data, incorrect identification of a party, routing difficulty. The invoice must be corrected and sent again through the electronic channel.
• Refusal by the buyer: it must be justified, for example when the company receiving the invoice is not the intended recipient. That is what happens when the SIREN entered belongs to another company.

In both cases payment waits for the correction, and you must keep a record of the rejection and of how it was fixed. Failing to issue invoices electronically is also punished by a fine per invoice, within the limits set by article 1737 of the General Tax Code.

In a customer file, the most frequent mistakes are well known:

• the SIREN is missing, because the customer was created from its name alone;
• a digit was swapped or left out when typing;
• a 14-digit SIRET was entered instead of the SIREN, or the other way round;
• the SIREN belongs to a closed, absorbed or restructured company;
• the SIREN belongs to another company of the same group, or to a company with the same name.

Cleaning your customer file in four steps

1. Extract the customers you invoice: your internal reference, the name, and any SIREN, SIRET or VAT numbers you already hold.
2. Verify each number: it must exist and belong to an active company, and the numbers of a single customer must agree (the SIRET belongs to the SIREN, the VAT number matches the company).
3. Fill in the missing numbers: look the company up by name and postcode, and ask the customer to confirm the number when several companies share a name.
4. Keep the file right: a company can close, move or be absorbed. Monitor your main customers instead of re-checking everything before each invoicing run.

A SIREN carries a built-in check digit that catches typing mistakes. But a correct digit proves neither that the company exists nor that it is still active: only looking up the company itself tells you that.

With Companies: a verified file in a few minutes

Without writing code, in your account area under Enrichment: upload a CSV file, choose the column holding the identifiers (SIREN, SIRET, French, Belgian or Swiss VAT number) and get the completed file back. Only the chosen column is sent. Each row comes back with, among other things, the name, status, legal form, address, VAT number and its status, the closing date, the insolvency signals, and an error column that explains the rows that were not recognised. A sample file of a few rows is offered next to the upload button to get you started. A file can hold up to 100 rows with the free account, 10,000 with Standard and 100,000 with Pro.

In your software, when you create or edit a customer record, a call to GET /v2/validate checks the SIREN, the SIRET and the VAT number at once:

curl "https://companies.jsonpage.com/v2/validate?id=FR-652014051&vat=FR14652014051" \
  -H "X-API-Key: $COMPANIES_API_KEY"

The response gives valid (true only if everything is correct) and the detail of each check: format, existence, active company, consistency of the numbers and VAT number status. For a customer without a SIREN, the name search suggests matching companies with their postcode and city; the article What is a SIREN number and how to find it shows how.

Keep reading

• SIRENWhat is a SIREN number and how to find itThe 9-digit format, who gets one, where it appears and how to find a company's SIREN from its name.
• SIREN · SIRETSIREN vs SIRET vs NIC: what is the difference?The company and its establishments: 9 or 14 digits, the role of the NIC and the right number for each use.
• VATFrench VAT number: format and how to check itThe French, Belgian and Swiss formats, the mentions on the invoice and the check before invoicing.