TL;DR — Quick Summary

Fix Aspel SAE CFDI invoice errors: failed stamping, expired CSD, missing CFDI 4.0 required fields, incorrect VAT setup, and PAC connection timeouts.

When you try to issue an electronic invoice in Aspel SAE and see “Error al timbrar comprobante”, “El RFC del emisor no coincide con el certificado”, or the XML generates with a total of $0.00, normal operations grind to a halt. These errors have specific causes — expired PAC credentials, an expired CSD, incomplete CFDI 4.0 fields — and this article walks you through the fix for each one.

The Error

The most frequent errors when generating CFDI invoices in Aspel SAE are:

  • “Error al timbrar comprobante” — appears when clicking Stamp in the Invoices module.
  • “El RFC del emisor no coincide con el certificado digital” — SAE detects the configured RFC does not match the loaded CSD.
  • “Error en la estructura del XML” — mandatory CFDI 4.0 fields are missing or incorrectly formatted.
  • “Error de conexión con el PAC” — timeout when connecting to Facturama, Finkok, or SW Sapien.
  • Invoice generated with $0.00 total — taxes are not assigned to the item or are misconfigured.
  • Complemento de Pago or Carta Porte with missing fields — the complement rejects stamping due to incomplete required fields.

These errors can occur individually or together, especially at month-end when PAC server load is high.

Root Cause

PAC — Expired or misconfigured credentials

The PAC (Authorized Certification Provider) acts as the intermediary between your company and the SAT. Its access credentials (username/password or token) have a limited lifespan. If they expire or are changed on the PAC portal without updating SAE, every stamping attempt will fail with an authentication error.

CSD — Expired or incorrect Digital Seal Certificate

The CSD is valid for 4 years from issuance. Once expired, the SAT rejects any CFDI signed with that certificate. Another common issue is loading a CSD from a different company or from an individual when the business is a corporation.

Missing CFDI 4.0 fields

Since January 2022, CFDI 4.0 is mandatory in Mexico. Unlike CFDI 3.3, it now requires: the recipient’s full legal name (exactly as it appears at the SAT), the recipient’s tax regime, and the postal code of the fiscal domicile. If any field is missing or does not match SAT records, the PAC rejects the stamping.

Incorrect tax configuration

Each item in SAE must have a tax type explicitly assigned. If an item has no VAT configured, the invoice is generated without tax — and the total may show as $0.00 if prices are entered net of VAT.

Step-by-Step Solution

Step 1 — Verify and update PAC credentials

  1. In Aspel SAE go to Configuración > Parámetros del Sistema > Facturación Electrónica.
  2. In the PAC section, confirm the provider name (Facturama, Finkok, SW Sapien, or other).
  3. Verify that the RFC, username, and password match exactly what is in your PAC portal.
  4. Click Probar Conexión. If it fails, log in to your PAC’s web portal and confirm credentials are correct and the account is active.
  5. For Facturama: go to facturama.io > Configuración > API and regenerate credentials if needed.
  6. Save changes in SAE and retry stamping.

Step 2 — Renew the expired CSD

  1. Go to the SAT portal: sat.gob.mx.
  2. Navigate to Trámites > Servicios > Certificado de Sello Digital.
  3. Use CertiSAT Web or SOLCEDI to generate a new CSD. You will need your valid e.firma (FIEL).
  4. Download the files: certificado.cer and private key.key.
  5. In Aspel SAE go to Configuración > Datos de la Empresa > Certificado Digital.
  6. Load the .cer file, then the .key file, and enter the private key password.
  7. Confirm the displayed validity date is in the future and the certificate RFC matches the company RFC.

Important: If your e.firma is also expired, you must renew it at the SAT first (in-person appointment required). Without a valid e.firma you cannot obtain a new CSD.

Step 3 — Complete CFDI 4.0 fields in the customer catalog

  1. In SAE, open Catálogos > Clientes and edit the customer that is causing the error.
  2. Fill in these mandatory fields:
    • Name / Razón Social: exactly as it appears on the customer’s constancia de situación fiscal.
    • RFC: valid and active at the SAT.
    • Régimen Fiscal: select the correct code (e.g., 601 - General de Ley Personas Morales, 612 - Personas Físicas con Actividades Empresariales, 626 - Simplificado de Confianza).
    • Código Postal del Domicilio Fiscal: the postal code registered at the SAT, not the delivery address.
    • Uso del CFDI: select the appropriate code (G03 - Gastos en general is the most common).
  3. Save changes and retry the invoice.

To verify the recipient’s exact data, request their Constancia de Situación Fiscal or use the SAT’s RFC validation service.

Step 4 — Fix tax configuration on items

  1. In SAE, go to Catálogos > Artículos and open the item with the problem.
  2. On the Prices/Taxes tab, verify that a tax is assigned.
  3. Assign the correct tax:
    • IVA Trasladado 16%: for most products and services.
    • IVA Trasladado 0%: for food, medicines, and other zero-rate items.
    • Exento: for operations not subject to VAT.
  4. If the tax catalog is empty, go to Configuración > Catálogos > Impuestos and create the corresponding tax.
  5. Enable “Precios con IVA incluido” or “Precios sin IVA” according to how you enter prices, so the calculation is correct.

Step 5 — Resolve Complemento de Pago and Carta Porte errors

Complemento de Pago (Payment Receipt):

  • Verify the original invoice is stamped with a valid UUID.
  • The paid amount in the complement cannot exceed the outstanding balance.
  • The payment method (01-Cash, 03-Wire Transfer, 04-Check, etc.) must be selected.

Carta Porte (Bill of Lading):

  • Requires carrier data (RFC, name, SCT permit).
  • Origin and destination locations must include complete addresses with postal codes.
  • Transported goods require description, weight, unit of measure, and value.

Step 6 — Verify and store the generated XML

  1. After successful stamping, SAE saves the XML to the configured path.
  2. Check the path at Configuración > Parámetros del Sistema > Facturación Electrónica > Ruta de XML.
  3. If the folder does not exist or lacks permissions, create it and grant write permissions to the Windows user running SAE.
  4. Validate the XML at: verificacfdi.facturaelectronica.sat.gob.mx using the stamp UUID.
  5. Send both the XML and PDF of the invoice to the customer.

Alternative Solution

If you need to stamp urgently and the PAC is unresponsive (common at month-end), use your PAC’s web portal directly:

  1. Go to facturama.io, finkok.com, or your PAC’s portal.
  2. Upload the XML generated by SAE (without a stamp) directly to the portal.
  3. The portal will stamp it and return the sealed XML.
  4. Import the stamped XML back into SAE using Archivos > Importar CFDI.

This is a valid workaround but breaks the automatic flow; use it as a temporary measure only.

Prevention

  • Check CSD validity every 6 months. Set a reminder 60 days before expiry.
  • Keep PAC credentials current in SAE. If you change your PAC password, update SAE the same day.
  • Validate customers with their constancia de situación fiscal when adding them. Do not rely on verbal data.
  • Keep Aspel SAE updated to the latest version. Each update includes corrections to SAT catalogs.
  • Avoid stamping in the last hours of the 31st of each month. PAC load is highest between 18:00 and midnight.
  • Monitor your PAC folio plan. If you exhaust available folios, stamping will fail.

EEFFACE error when opening Aspel SAE

If SAE does not start and shows EEFFACE, it is a database connection issue, not an invoicing one. Check the database server and the Aspel license server.

”Missing Data Provider” error in SAE

This error indicates the database engine is not installed correctly. Reinstall the Aspel SAE data components from the original installer.

Cancelling a CFDI

To cancel an already-stamped CFDI in SAE:

  1. Open the invoice and select Cancelar CFDI.
  2. Choose the cancellation reason: 01 (Invoice with errors — related substitute exists), 02 (Invoice with errors — no substitute), 03 (Transaction did not occur), 04 (Global invoice transaction).
  3. For reason 01, enter the UUID of the replacement CFDI.
  4. The recipient has 72 hours to accept or reject the cancellation from their SAT tax inbox.

Summary

  • Stamping errors in Aspel SAE have defined causes: misconfigured PAC, expired CSD, incomplete CFDI 4.0 fields, or unconfigured taxes.
  • First verify PAC credentials using the “Probar Conexión” button in SAE parameters.
  • Renew the CSD from the SAT portal at least 60 days before it expires.
  • CFDI 4.0 requires the recipient’s name, RFC, tax regime, and postal code exactly as registered at the SAT.
  • Each item must have its VAT type assigned (16%, 0%, or Exempt) for invoices to calculate correctly.
  • Always validate the final XML in the SAT verifier to confirm the digital seal.