MATRET - SECUline

What is MATRET? — MATRET is a response file generated by the Joint Social Security Centre (CCSS) through the SECUline system that reports unprocessable records from the DEMMAT file. When employers submit a DEMMAT request to obtain social security numbers for new employees, MATRET provides feedback on requests that cannot be processed, along with specific rejection codes explaining why each request was rejected.

When does an employer receive a MATRET file? — Employers receive a MATRET file when the CCSS cannot process their social security number request submitted via DEMMAT. This typically occurs during the employee onboarding process when the employer is attempting to obtain a social security number (matricule) for a new employee, particularly for EU, EEA, or Swiss nationals who are working in Luxembourg for the first time and do not yet have a Luxembourg social security number.

What information does a MATRET file contain? — The MATRET file contains the original social security number requests from the DEMMAT submission, supplemented with rejection codes that identify specific issues preventing processing. Each record includes the employee information originally submitted and a rejection code (field number 2) that specifies exactly why the CCSS cannot create the social security number. The file is structured as an ASCII-encoded text file with fields separated by semicolons and follows the naming convention MATRET.xxxx_yyyy_zzzz.dta, where xxxx represents the employer registration number, yyyy is the SECUline number, and zzzz is a timestamp.

How should an employer respond to a MATRET rejection? — Upon receiving a MATRET file with rejection codes, employers must correct the identified issues and resubmit the request. Depending on the rejection reason, this may involve scanning a new identity document through the CARTID procedure with better quality or in color, correcting data errors in the DEMMAT file, providing complete or current identification documents, or following alternative procedures such as directing non-EU nationals to the Direction Générale de l'Immigration. Once corrections are made, the employer resubmits both the corrected DEMMAT and CARTID files through SECUline.

Why is MATRET important in Luxembourg payroll processing? — MATRET is essential for maintaining accurate employee records and ensuring compliance with Luxembourg social security regulations. Without a valid social security number, employers cannot complete the declaration of entry (DECAFF) required within eight days of hiring an employee. The CCSS considers any subsequent records submitted with an invalid social security number to be null and void, making it the employer's responsibility to resolve MATRET rejections promptly 
to avoid compliance issues and delays in properly registering new employees in the Luxembourg social security system.

What is the relationship between DEMMAT, CARTID, MATRET, and MATASS? — These files work together in a sequential workflow for obtaining social security numbers through SECUline. The process begins when the employer submits a DEMMAT request with employee details and a CARTID file containing a scanned identity document. If the request cannot be processed, the CCSS responds with a MATRET file indicating the rejection and reason. After the employer corrects the issues and resubmits, the CCSS then provides a MATASS file confirming the newly created social security number, allowing the employer to proceed with the DECAFF declaration of entry.

Synonyms: Social security number rejection file, DEMMAT rejection response, matricule rejection notice, SECUline rejection file