Infonavit Amortization Error in SUA

The Sistema Único de Autodeterminación (SUA) is the mandatory tool in Mexico for employers to calculate IMSS quotas and Infonavit amortizations.

A very common problem is when the amortization calculation (housing credit discount) in SUA does not match what Infonavit charges in the Early Bimonthly Issuance (EBA).

Prerequisites

  • SUA updated to the latest version.
  • Original Infonavit Retention Notice.
  • Current values for UMA, UMI, and Minimum Wage.

Common Causes and Solutions

1. Incorrect or Missing Discount Factor

Verify the Retention Notice. In SUA (Update → Workers → Infonavit Tab), ensure the correct discount type is selected:

  1. Percentage (1): Discounts a percentage of the Base Quotation Salary (SBC).
  2. Fixed Monetary Fee (2): A fixed amount in pesos.
  3. Discount Factor in VSM/UMI (3): The factor multiplied by the UMI value.

2. Unupdated Units (UMI/UMA)

Since 2016, VSM credits use the Mixed Infonavit Unit (UMI).

  1. Go to Update → INFONAVIT Value → UMI.
  2. Add the current value (e.g., 01/01/2024 - $100.81).
  3. Click Update.

3. Incorrect SBC (Base Quotation Salary)

For percentage-based credits, the calculation depends on the SBC. Ensure all salary modifications are registered with exact dates.

4. Unreported Incidents

SUA calculates based on worked days. Ensure all absences and medical incapacities are captured in Update → Workers → Movements before doing the global calculation.

Verification Summary

  1. Download the EBA from IDSE.
  2. Generate a global calculation in SUA.
  3. Print the Determination Schedule.
  4. Compare worker by worker.