Imss — St-9

File a Reanudación de labores ST-9 on the exact day the employee returns.

The term "ST-9 IMSS" refers to the standardized format (form ST-9) used to report wages, contributions, and employee data modifications. It serves as the official notice for changes in salary, temporary work stoppages, reinstatements, or adjustments to the Integration Factor (Factor de Integración). Failure to properly file this form can lead to severe penalties, audits, and legal liabilities. st-9 imss

Submit the form. The system generates an Acuse de Recepción (acknowledgment receipt) with a unique folio. Save this PDF indefinitely—it is your legal proof of timely filing. File a Reanudación de labores ST-9 on the

If daily salary = $500 MXN, aguinaldo = 15 days/year, vacation premium = 25% of 12 vacation days: Daily aguinaldo = (500 × 15) / 365 = $20.55 Daily vac premium = (500 × 12 × 0.25) / 365 = $4.11 Total SBC = $500 + $20.55 + $4.11 = $524.66 MXN Failure to properly file this form can lead

Use certified payroll software (e.g., Aspel , Contpaq i , SAP SuccessFactors ) that automatically calculates the SBC and generates the ST-9 XML file for direct upload to IMSS.

The ST-9 is not a recurring monthly form like the standard contribution determination. It is an . You must file an ST-9 when any of the following occur: