TL;DR — Quick Summary

SUA IMSS quota calculation errors: fix SBC capped at 25 UMA, import IDSE movements, reconcile SIPARE file, and configure Infonavit amortization discount types.

The “Error al calcular cuotas obrero-patronales” message in the IMSS SUA software blocks bimonthly payroll closing and can trigger surcharges if not resolved before the payment deadline. This article covers the most frequent specific causes: SBC exceeding the 25 UMA cap, IDSE movements not correctly imported, differences between the bimonthly calculation and the SIPARE file, sick leave not reducing credited days, Infonavit discount configuration errors, and the EMA file not loading properly.

The Error

When running Determinación de cuotas > Cálculo for the corresponding period, SUA may display:

“Error al calcular cuotas obrero-patronales”

“El SBC del trabajador supera el límite máximo de cotización”

“No existen movimientos para el período seleccionado”

“Error al leer archivo de Emisión Mensual Anticipada”

The error can also appear silently: the calculation completes without a message, but the generated SIPARE file shows significant differences from the amounts the IMSS expects, resulting in rejections or payment discrepancies.

Root Cause

SUA integrates four data sources to calculate each bimonthly quota: affiliation movements imported from IDSE, each worker’s SBC, the actual credited days (adjusted for sick leave), and the current contribution rate tables. An error in any of these produces incorrect results.

SBC Exceeding the 25 UMA Cap

The SBC (Salario Base de Cotización) has a maximum cap equal to 25 times the daily UMA value. For 2026, the daily UMA is $113.14, giving a cap of $2,828.50/day. If the worker’s actual salary exceeds this limit, SUA must record the SBC at exactly that cap — not the real salary. An SBC captured above the cap triggers a validation error that prevents calculation.

Concept2026 Value
Daily UMA$113.14
Maximum cap (25 × UMA)$2,828.50/day
Approximate monthly cap$85,855.00
General minimum wage$278.80/day

IDSE Movements Not Imported or With Errors

IDSE (IMSS Desde Su Empresa) is the official platform for submitting hires, terminations, and salary modifications. If these movements are not imported into SUA — or if they are imported with format errors — SUA lacks the information needed to determine who contributed during the period. The most common issues are:

  • The IDSE response file was downloaded incomplete or corrupted.
  • Movements remained with Rechazado (Rejected) status in IDSE and were never corrected.
  • Salary modifications have dates outside the bimonthly period being calculated.
  • Modifications were made directly on the IMSS web portal without importing the result into SUA.

Bimonthly Calculation Not Matching SIPARE

Differences between SUA’s calculation and the IMSS SIPARE file typically stem from:

  • Unregistered sick leave: General illness days reduce the employer’s quotas. If SUA doesn’t have the sick leave records, it calculates as if the worker contributed every day of the period.
  • EMA not loaded: The Emisión Mensual Anticipada published by IMSS on IDSE contains corrections and adjustments. If it’s not downloaded and imported into SUA before calculation, the base amounts differ.
  • RCV calculated with wrong SBC: The RCV (Retiro, Cesantía y Vejez) calculation uses the SBC for the corresponding month. If there was a salary modification mid-period, SUA must use the days contributed at each SBC separately.

Infonavit Discounts Misconfigured

Infonavit issues a discount notice specifying the type and amount of each worker’s credit. The three valid types are:

TypeDescriptionExample
Type 1Percentage of SBC10% of daily SBC
Type 2Fixed peso amount$1,250.00/month
Type 3Multiple of minimum wage (VSM)0.5 VSM/month

If the discount type configured in SUA doesn’t match the notice, SUA calculates a different amortization from what Infonavit expects, creating differences requiring supplemental payments.

Step-by-Step Solution

Step 1: Verify SBC Against the UMA Table

  1. Open SUA and go to Afiliación > Consulta/Modificación de trabajadores.
  2. Sort the list by SBC from highest to lowest.
  3. Identify all workers with SBC greater than $2,828.50 (2026 cap).
  4. For each, edit the record and set the SBC to exactly the maximum cap.
  5. Also verify no worker has SBC below the minimum wage ($278.80/day).

If using Aspel NOI or CONTPAQi Nóminas, check the SDI configuration in your payroll system and verify the export process to SUA correctly applies the contribution cap instead of the actual salary.

Step 2: Import Pending IDSE Movements

  1. Access the IDSE portal at idse.imss.gob.mx with your digital certificate.
  2. Download the response file (acknowledgment of submitted movements).
  3. In SUA, go to Utilerías > Importar movimientos afiliatorios.
  4. Select the downloaded response file.
  5. Review the list of imported movements. Any showing Rechazado must be corrected and resubmitted through IDSE.
  6. If movements for the period were entered directly on the IMSS web portal (not through IDSE), enter them manually in SUA via Afiliación > Movimientos afiliatorios.

Step 3: Register Sick Leave Correctly

  1. Go to Afiliación > Incapacidades in SUA.
  2. For each sick-leave certificate in the bimonthly period, enter:
    • Worker’s NSS
    • Certificate folio number
    • Type of leave (general illness, work accident, maternity)
    • Start date and number of days
  3. SUA will automatically reduce the worker’s credited days.
  4. Work accident and maternity leave do NOT reduce employer quotas; only general illness generates an adjustment.

Step 4: Load the EMA Before the Bimonthly Calculation

  1. On the IDSE portal, download the Emisión Mensual Anticipada for the corresponding period.
  2. In SUA, go to Utilerías > Cargar EMA.
  3. Select the downloaded EMA file.
  4. Verify SUA confirms successful loading for the correct period.
  5. Only after loading the EMA should you run the bimonthly calculation.

Step 5: Verify Infonavit Discounts and RCV

  1. Go to Afiliación > Créditos Infonavit in SUA.
  2. For each worker with an active credit, confirm the discount type (1, 2, or 3) exactly matches the Infonavit discount notice.
  3. Verify the amount or percentage entered matches the notice.
  4. For RCV calculation, go to Afiliación > Consulta/Modificación and confirm the SBC history for the period correctly reflects each salary modification with its exact date.

Step 6: Generate and Validate the SIPARE File

  1. With all data corrected, go to Determinación de cuotas > Cálculo.
  2. Select the bimonthly period and year. Run the calculation.
  3. Review the differences report SUA generates showing calculated amounts worker by worker.
  4. When the calculation succeeds, go to Procesos > Generación de archivo SIPARE.
  5. Save the generated .SUA file.
  6. Access the SIPARE portal (www.imss.gob.mx/sipare) and load the file for online validation before sending it to the bank.

Alternative Solution

If the payroll system (Aspel NOI or CONTPAQi Nóminas) does not correctly export the SBC to SUA, you can reconcile data manually:

  1. Export an SDI (Integrated Daily Salary) report by worker for the period from your payroll system.
  2. Compare against the SBC values registered in SUA.
  3. For workers with differences, edit the SBC directly in SUA with the correct SDI value (applying the 25 UMA cap where applicable).
  4. Manually enter any salary modifications from the period that were not imported from IDSE.

If the SIPARE portal doesn’t accept the file generated by SUA, you can generate the payment line directly from IMSS Digital (www.imss.gob.mx) without needing the SUA file, using your NPIE (employer identification number) or e.firma.

Prevention

  • Apply the 25 UMA cap from the payroll system: Configure Aspel NOI or CONTPAQi Nóminas to automatically apply the contribution cap when exporting SDI to SUA, rather than exporting the actual salary.
  • Import IDSE movements the same day you submit them: Don’t let pending response files accumulate, especially near bimonthly closing.
  • Register sick leave in real time: Enter each certificate in SUA as it occurs, not at the end of the period.
  • Download the EMA monthly: IMSS publishes the Emisión Mensual Anticipada between the 17th and 20th of each month. Download and import it to SUA immediately.
  • Verify Infonavit discount notices at year start: Discount types and amounts can change. Update SUA when new notices arrive.
  • Reconcile against payroll monthly: Compare total quotas calculated by SUA against your payroll system’s quota summary before bimonthly closing to catch differences early.
ProblemMost Likely CauseAction
EMA won’t load in SUAExpired digital certificate on IDSERenew certificate and re-download EMA
SIPARE file rejected at bankEmployer RFC doesn’t match IMSS recordsCheck RFC in Configuración > Datos del patrón
RCV differs from payrollMid-period salary modifications not reflectedEnter modification movement with exact date in SUA
Infonavit deducts wrong amountWrong discount type (1/2/3) configuredFix type to match Infonavit discount notice
Zero quotas for a workerHire movement not imported from IDSEImport hire movement or enter it manually
Error opening EMAOutdated SUA versionUpdate SUA from the IMSS portal

Summary

  • The maximum contribution cap is 25 times the daily UMA ($2,828.50 in 2026). The SBC must never exceed this.
  • IDSE movements (hires, terminations, modifications) must be imported into SUA with Aceptado status before the bimonthly calculation.
  • General illness sick leave reduces credited days and must be entered in SUA for accurate calculation.
  • The EMA must be loaded into SUA before running the bimonthly calculation to avoid discrepancies with IMSS amounts.
  • Infonavit discounts have three types (percentage, fixed amount, VSM); the configured type must exactly match the discount notice.
  • If the local calculation doesn’t match SIPARE, you can pay directly from IMSS Digital as a temporary workaround.