The Fundamental Rule: Uniqueness and Continuity
In France, Article 242 nonies A of Annex II of the CGI requires every invoice to carry a unique number based on a chronological and continuous sequence. Any break in sequence may trigger a tax audit.
Accepted Numbering Formats
Valid format examples · French tax law
All these formats are legally valid — the key rule: no gaps in the sequence
- Simple sequential: 00001, 00002, 00003…
- With year prefix: 2024-001, 2024-002…
- With custom prefix: INV-2024-001, QUO-2024-001…
- Dedicated series: if you carry out several distinct activities, one series per activity is permitted.
What Is Strictly Forbidden
It is forbidden to delete an issued invoice, reuse a number, leave a gap in the sequence or backdate a number. During an audit, these anomalies are major red flags for the tax authorities.
Electronic invoicing becomes mandatory in France from 2026 for all VAT-registered businesses. Tools such as Devis IA are already compliant with this framework.
How Devis IA Handles This Automatically
Devis IA uses server-side atomic numbering: each new document receives the next available number irreversibly, even when used simultaneously across multiple devices. No gaps, no duplicates.
Tax compliance is not an extra burden when the right tools handle it for you in the background.