After defining one or more legal employers for your enterprise, you set up one or more government reporting entities (GREs) within each legal employer. GREs represent an employer's relationship with the Social Security organizations in Mexico. They are the entities responsible for all statutory reporting related to Social Security in Mexico. You must have a separate GRE for every Social Security ID assigned to you by the Social Security agencies.
The Social Security agencies consider the GRE to be the employer (not the legal employer), and so all transfers into and out of a GRE must be reported to Social Security as hires and terminations.
The social security agencies assign each GRE an 11-character Social Security ID (1 alphabetical character and 10 digits).
The GRE is the entity responsible for all matters related to Social Security Affiliation Process reporting. It records the tax subsidy percentage, Work Risk Incident Premium (WRIP), and Economic Zone. In addition, while you define the average days per month and average days per year values at the Legal Employer level, the GRE can override these values.
The Generic Hierarchy defines the relationship between GREs and Locations. A GRE can have multiple locations, and a location can have multiple GREs.
The Social Security agencies assign GREs according to economic zone and business operation:
If a company has multiple work places in the same municipality, and they share the same business activity, then the company has only one Social Security Employer Number. In this case, all locations operate in only one GRE.
If a company has multiple work places in the same municipality, and their activities are different, then the Social Security agencies assign separate IDs. In this case, there are different GREs for each work place (even if they share the same Location).
The Employer and the Social Security agencies may establish an agreement whereby the Employer can report the information for all locations using the same Social Security Employer Number. In this case, you would require only one GRE.
Unless manually overridden, employees inherit their GRE based on their assignment's location.