Updated on
27/11/2025
CARTID - SECUline
What is CARTID? - CARTID is a digital procedure within the SECUline system used by employers to transmit scanned identity documents to the Joint Social Security Centre (CCSS) in Luxembourg. This procedure is required when requesting a social security number for new employees who do not yet have one through the DEMMAT procedure.
When is CARTID used? - Employers must use CARTID when hiring employees for the first time in Luxembourg who do not have a Luxembourg social security number. The procedure applies to both EU, EEA, Swiss nationals and residents who need initial registration with the social security system. CARTID accompanies every DEMMAT request to verify the employee's identity.
What documents are acceptable for CARTID submission? - Only official identity documents are accepted through CARTID:
- Valid identity cards (national ID cards)
- Valid passports
- Civil status records stating nationality
Documents like residence permits, visa cards, or expired identity documents are not accepted and will result in rejection of the registration request.
What are the technical requirements for CARTID files? - The CCSS has strict specifications to ensure document legibility:
- Format: JPEG file only
- Resolution: Between 100 and 300 dpi
- File size: Maximum 3 MB
- Compression: Must not exceed 30%
- Color depth: 24-bit color mandatory
- Both sides of identity cards must be scanned in color when data appears on front and back
The scanned image must be cropped appropriately without cutting off any data, and the quality must allow verification of all identity information and the photograph.
How is the CARTID file named? - Files follow a specific naming convention when sent via SECUline's SOFiE system: CARTIDyyyymmddn.xxxxxxxxxxxxx_yyyyyy.JPG where yyyy represents the employee's year of birth, mm the month, dd the day, n is a serial number (starting at 0), xxxx is the employer's registration number, and yyyyyy is the SECUline number. If multiple employees share the same birthdate, the serial number increments sequentially.
What happens if CARTID submission is rejected? - The CCSS communicates rejection reasons through the MATRET file with specific error codes. Common rejection reasons include insufficient image quality, incomplete documents, expired identification, or unacceptable document types. Employers must correct the issue and resubmit both the DEMMAT and corrected CARTID files.
How does CARTID fit into the employee registration process? - CARTID is one step in a multi-file procedure for registering new employees. Employers first submit DEMMAT (social security number request) along with CARTID (identity document scan). If accepted, the CCSS responds with MATASS (social security number confirmation), after which employers complete DECAFF (declaration of entry) to finalize employee affiliation.
Synonyms: Identity document transmission, scanned ID procedure, CCSS document upload