TL;DR — Quick Summary

Fix Aspel NOI SUA export errors: set a writable export path, validate IMSS format, employer registry, NSS and SDI before importing movements into SUA.

Diagrama

When Aspel NOI fails to export affiliation movements to the IMSS SUA file, payroll teams are stuck between a correctly captured payroll in NOI and a SUA instance that needs those movements for bimonthly quota calculation and SIPARE payment. The error may appear as an explicit export message, an empty file, or a file SUA rejects on import with dozens of Rejected records.

This guide covers common technical and data causes in Mexico, step-by-step correction, and practices to prevent recurrence at each bimestre close.

The Error

When running Processes > IMSS > Export movements to SUA, NOI may show:

“Error generating affiliation movement file”

“Cannot write to the specified export path”

“Employer registry is not valid”

“Workers with incorrect NSS exist”

Even when NOI reports success, SUA may reject the file on import:

“File structure error”

“NSS not found in registry”

“SDI outside allowed range”

Root Causes

NOI → SUA export is not a simple data dump. Aspel must transform payroll data into the exchange format SUA expects: fixed-length fields, specific encoding, valid movement types (hire=1, termination=2, salary change=7, rehire=8), and cross-validation against employer registry and worker NSS.

Outdated NOI version

Aspel publishes periodic re-installables that update IMSS export routines. An older NOI version may generate a layout obsolete for the current SUA — especially after UMA or SDI cap changes for 2026.

Wrong employer registry

The registry in NOI must match IMSS records exactly: 11 alphanumeric characters, no spaces or dashes. One wrong digit causes SUA to reject the entire batch.

Location: Configuration > Company > IMSS Data > Employer registry.

Invalid NSS format or check digit

Each worker needs an 11-digit NSS with a valid check digit. Capture errors — swapped digits, another worker’s NSS, provisional NSS never updated — cause individual or mass rejection on SUA import.

SDI outside allowed range

SDI must reflect daily salary plus integrable benefits and cannot exceed the 25-UMA contribution cap ($2,828.50 daily in 2026). Run Processes > Recalculate SDI before each bimonthly export.

Export path without permissions

Common issues:

  • UNC network folder with insufficient Windows user permissions.
  • Path inside OneDrive or similar syncing tools that lock files.
  • Antivirus quarantining the freshly generated .txt.
  • Full disk or nonexistent path.

Inconsistent affiliation movements in NOI

Before export, NOI validates internal consistency:

  • Overlapping hire and termination dates.
  • Salary change dated before hire.
  • Rehire without prior termination.
  • Movements outside the selected export bimestre.

Step-by-Step Fix

1. Update NOI and confirm SUA compatibility

Install the latest Aspel NOI re-installable for the fiscal year. Confirm SUA on the workstation matches imss.gob.mx. Document both versions.

2. Validate employer registry

In Configuration > Company > IMSS:

  • Employer registry: exactly 11 characters.
  • Legal name matching IMSS registration.

Compare against the IMSS employer registration certificate.

3. Audit workers: NSS, SDI, movements

  1. Catalog > Workers — review NSS for each active employee.
  2. Processes > Recalculate SDI — apply to all workers in the period.
  3. Reports > Affiliation movements — find duplicates, out-of-range dates, pending items.
  4. Fix in NOI before export; never patch the .txt manually.

4. Configure a reliable export path

  1. Create C:\Aspel\Export\SUA\ on local disk.
  2. Grant modify permissions to the NOI user.
  3. Exclude the folder from real-time antivirus if needed.
  4. In NOI: Processes > IMSS > Export to SUA — point to that path.

Test with a single worker before the full batch.

5. Export, import in SUA, reconcile

  1. Select bimestre and movement types.
  2. Generate the .txt from NOI.
  3. In SUA: Utilities > Import affiliation movements.
  4. Review the report — all records must be Accepted.
  5. If rejected, fix in NOI and re-export.

After successful import, proceed with bimonthly calculation in SUA.

Prevention

  • Export movements weekly, not only at bimestre close.
  • Pre-export checklist: registry, NSS, recalculated SDI, updated NOI.
  • Document a fixed export path across workstations.
  • Back up NOI database before re-installable updates.

Summary

  • NOI → SUA export errors usually stem from outdated NOI, wrong registry, invalid NSS/SDI, or blocked export paths.
  • Update NOI, validate worker data, and use a local writable folder.
  • Import in SUA and confirm Accepted status before bimonthly calculation.
  • Never manually edit the .txt; fix in NOI and re-export.