MATASS - SECUline

What is MATASS? — MATASS is a file communication procedure within SECUline, the electronic data exchange platform operated by the Joint Social Security Centre (CCSS). This file transmits the validated social security number of an employee from the CCSS to the employer after a registration request has been processed. The MATASS file is a critical component in Luxembourg's digital employee registration workflow, ensuring employers receive accurate social security identification numbers for their workforce.

When does an employer receive a MATASS file? — Employers receive a MATASS file after submitting a DEMMAT request (social security number application) through SECUline for a new employee who does not yet have a Luxembourg social security number. Once the CCSS processes the request and validates the employee's identity information, it generates the MATASS file containing the newly assigned or confirmed social security number. This typically occurs when hiring employees for their first position in Luxembourg, such as cross-border workers who have never worked in the Grand Duchy before.

What information does the MATASS file contain? — The MATASS file is a text file that contains the employee's valid Luxembourg social security number along with identifying information that allows the employer to match it to the correct employee record in their payroll system. The file follows a standardized format with fields separated by semicolons and uses ASCII encoding. The file naming convention follows the pattern MATASS.xxxx_yyyy_zzzz.dta, where xxxx represents the employer registration number, yyyy is the SECUline number, and zzzz is a timestamp.

Why is the MATASS file important for payroll processing? — The MATASS file is essential because the CCSS considers any subsequent records submitted with an invalid or missing employee social security number as null and void. Employers must record the valid social security number provided in the MATASS file into their payroll database to ensure all future submissions are processed correctly. This includes affiliation declarations through the DECAFF file and monthly wage declarations. Without the correct social security number, employers cannot properly register employees or submit compliant payroll data to Luxembourg authorities.

How does MATASS fit into the employee registration process? — The MATASS file is part of a four-step electronic workflow for registering new employees without existing Luxembourg social security numbers. First, the employer submits a CARTID file containing a scanned identity document. Second, the employer sends a DEMMAT file with the employee's contact details and registration request. Third, if the CCSS cannot process the request, it returns a MATRET file indicating errors that must be corrected. Fourth, once processing is successful, the CCSS sends the MATASS file with the assigned social security number. After receiving the MATASS file, the employer proceeds to submit the DECAFF file 
to complete the employee's affiliation with the Luxembourg social security system.

What should employers do after receiving a MATASS file? — Upon receiving a MATASS file, employers must immediately update their internal payroll database with the valid social security number provided. They should verify that the employee information in the MATASS file matches their records to avoid data inconsistencies. The employer then uses this validated social security number in the DECAFF affiliation declaration and all subsequent payroll-related communications with the CCSS. Maintaining accurate social security numbers is the employer's responsibility and is critical for ensuring compliance with Luxembourg labor and social security regulations.

Synonyms: Social security number communication file, CCSS employee number transmission, SECUline registration response