Salario Base de Cotización (SBC), meaning "Base Contribution Salary," is a critical payroll concept in Mexico. It represents the total daily compensation used to calculate employer and employee contributions to IMSS (social security) and INFONAVIT (housing fund). The SBC is not simply the base salary — it integrates most forms of compensation into a single daily figure.
Components Included in SBC
The SBC includes daily base salary, the proportional daily value of aguinaldo (Christmas bonus), vacation premium (prima vacacional), and any other regular cash or in-kind benefits. For example, a worker earning $15,000 MXN monthly with the legal minimum aguinaldo (15 days) and vacation premium (25%) would have an SBC higher than their simple daily salary.
Excluded Components
Certain payments are excluded from SBC: overtime (within legal limits), profit sharing (PTU), contributions to savings funds (within limits), food allowances (within limits), and productivity bonuses meeting specific legal criteria. Understanding these exclusions is essential for accurate contribution calculations.
EOR Relevance
An EOR in Mexico calculates the SBC for each employee and files the required modification notices with IMSS whenever compensation changes. Incorrect SBC calculations can trigger IMSS audits and result in back-payment of contributions plus surcharges and fines.