Sign an invoice electronically

An invoice does not need to be signed to be valid, but signing it electronically guarantees its origin and integrity: nobody can alter it afterwards without it showing. You still need to know what this signature replaces, and what it does not.

What the law says

The French General Tax Code (Code général des impôts) sets out the mandatory information on an invoice: identity of the seller and the buyer, number, date, description, price, VAT. The signature is not one of them.

An invoice sent as a PDF must, however, guarantee the authenticity of its origin, the integrity of its content and its legibility, from the day it is issued until the end of its retention period. An electronic signature or seal is one of the accepted ways of doing so, alongside a reliable audit trail and electronic data interchange (EDI).

The e-invoicing reform

Between businesses established in France, the electronic invoice is changing in nature: it must be issued in a structured format and sent through an approved platform. A PDF, even signed, is no longer enough for an invoice that falls within this scope.

The timetable is phased: all businesses must be able to receive electronic invoices since 1 September 2026; the obligation to issue them has applied to large companies and mid-sized companies (ETI) since that date, and applies to SMEs (PME) and micro-enterprises from 1 September 2027.

Signing a PDF therefore remains useful for invoices outside the scope of the reform: those addressed to private individuals, to customers established abroad, or issued before the obligation applies to your business.

What the signature brings

• Integrity: any change to the PDF after signing breaks the signature, and any PDF reader shows it.
• Origin: the signature bears your first and last names, and the evidence file records how it was applied.
• Date: a qualified timestamp fixes the moment of signing.

Which level to choose

• Level 1: the document receives a Goodflag eIDAS qualified seal, which guarantees its integrity, and your consent is collected through a code received by email.
• Levels 5 and 6: the qualified signature of the issuer themselves, the strongest.

Key points

• Sign the final version of the invoice: an issued invoice is not modified, it is cancelled by a credit note.
• Keep the signed PDF and its evidence file for the whole retention period of the invoice.
• Download them within seven days: we do not keep them beyond that.