French license plate formats: SIV and the legacy FNI system

France has had several registration systems throughout its history. Today, two formats still coexist in the vehicle fleet: the SIV system in use since 2009 and the legacy FNI system. For professionals integrating the license plate API, understanding these formats is essential for normalising inputs and correctly handling requests.

The legacy FNI system (1950-2009)

The National Registration File (FNI), established in 1950, used a department-based format. The plate number consisted of three elements:

• A sequential number of 1 to 4 digits (1 to 9999)
• A series of 1 to 3 letters (A to ZZZ)
• The department number (01 to 95, or 2A/2B for Corsica)

Example: 1234 AB 75 designated a vehicle registered in Paris. When the letter series was exhausted in a department (after ZZZ), the next number was used and the letters started again from A.

FNI limitations

The FNI system caused several operational problems:

• Change on every sale -- when ownership transferred to a different department, the plate changed, creating considerable administrative burden
• Capacity exhaustion -- the most populated departments (75, 92, 93, 69) quickly ran through their series
• IT complexity -- department-based management led to fragmented databases and difficult cross-referencing

The SIV system (since 2009)

The Vehicle Registration System was launched on 15 April 2009 to progressively replace the FNI. The format is national and permanent: AA-123-AA (two letters, three digits, two letters, separated by hyphens).

SIV principles

• Lifetime assignment -- the number stays with the vehicle from first registration to destruction, regardless of ownership or department changes
• National chronological series -- numbers are assigned in order with no geographic reference. The series started at AA-001-AA
• Excluded letters -- the letters I, O and U are excluded to avoid confusion with the digits 1, 0 and the letter V
• Capacity -- the system offers approximately 277 million combinations, sufficient for several decades

Series progression

The series advances logically: AA-001-AA, AA-002-AA, ..., AA-999-AA, AA-001-AB, ..., AA-999-ZZ, AB-001-AA, etc. The three digits advance first, then the last two letters, then the first two letters. By March 2026, the series has passed GX-000-XX, confirming the system is built to last.

Special plates

Certain vehicle categories have specific plate formats:

• Diplomatic plates -- specific numeric format with the country or international organisation code (e.g. 123 CD 456)
• Military plates -- format specific to the armed forces, not registered in the civilian SIV
• Provisional WW plates -- assigned to vehicles being registered (format WW-123-AA)
• Transit plates -- TTQ or TT for vehicles intended for export

How the API handles both formats

The AutomotivAPI license plate API accepts both plate formats. Whether you send an SIV plate (AB-123-CD) or an FNI plate (1234 AB 75), the API automatically normalises the format and queries the Ministry of the Interior's SIV database.

The normalisation also handles common input variations:

• With or without hyphens: AB123CD is equivalent to AB-123-CD
• With or without spaces for FNI: 1234AB75 is equivalent to 1234 AB 75
• Upper and lower case: case is ignored

This normalisation is transparent to the user: you send the plate as entered by your customer or detected by an ANPR camera, and the API handles the rest.

European context

The AutomotivAPI API also handles license plates from several European countries. Each country has its own format: B-AB 1234 in Germany, AB 123 CD in Italy, 1234-ABC in Spain. The API automatically detects the country of origin based on the format and queries the appropriate database.

To learn more about the license plate API, see our complete guide to the license plate API or our technical documentation.