When is a CFDI payment supplement (REP) required in Mexico?

A REP is required whenever an invoice was issued with payment method PPD (deferred or installment payment). It must be issued within 5 business days of receiving each payment.

Why does the PAC reject the payment supplement with a UUID error?

The UUID in the DoctoRelacionado node must exactly match the fiscal folio of the original income CFDI. If the invoice was cancelled, substituted, or already fully paid, the PAC will reject the supplement.

What should I do if the original invoice was PUE but payment came later?

If the invoice was issued as PUE but payment arrived later, you cannot issue a payment supplement for it. You must cancel the original invoice and reissue it with payment method PPD and form 99 (To be defined).

How do I enter the exchange rate in a USD payment supplement in Aspel SAE?

When registering a foreign-currency payment, enter the exchange rate published in the DOF (Diario Oficial de la Federación) for the day the payment was received. The supplement will automatically calculate the peso equivalent for the outstanding balance.

CFDI Payment Supplement (REP) Errors in Aspel SAE: Full Fix Guide

TL;DR — Quick Summary

Fix CFDI payment supplement (REP) errors in Aspel SAE: wrong UUID, PPD method, exchange rate, installment count, and PAC rejection codes explained.

When recording a payment against a Mexican invoice in Aspel SAE and generating the CFDI payment supplement (also called REP — Recepción de Pagos), errors such as “Error stamping the payment supplement”, “The related invoice UUID is not valid”, or “The previous balance does not match” are common. These errors block the issuance of the required document and can result in SAT penalties if unresolved.

The Error

The most common payment supplement errors in Aspel SAE appear as PAC (Authorized Certification Provider) messages at stamp time:

“Error CFDI33102: The UUID attribute does not exist in the SAT database” — the related CFDI fiscal folio is not recognized.
“Error CFDI33103: The related document has already been fully paid” — a supplement is being generated against a fully settled invoice.
“Error CFDI40180: The installment number is not the next consecutive value” — the NúmParcialidad field does not match the expected sequence.
“Previous balance does not match” — the ImpSaldoAnt differs from the ImpSaldoInsoluto of the preceding supplement.
“Timeout connecting to PAC server” — a transient communication issue.
“Payment form not valid for supplement” — the original invoice uses PUE method, not PPD.

These errors occur in Aspel SAE 9.0 and earlier versions, regardless of which certified PAC is used (Edicom, Finkok, Solucion Factible, etc.).

Root Cause

Payment supplement version 2.0 (mandatory since January 2022) requires that the data in the Pago and DoctoRelacionado nodes be mathematically consistent with the full payment history of the related income CFDI. The most frequent causes of errors are:

Wrong payment method on the original invoice. The invoice must have payment method PPD and payment form 99 to support a REP. PUE invoices cannot have supplements generated.
Incorrect or cancelled UUID. The UUID in DoctoRelacionado must refer to a valid, active income CFDI — not cancelled or substituted.
Wrong previous balance (ImpSaldoAnt). For the first supplement this must equal the full invoice amount. For subsequent supplements it must equal the ImpSaldoInsoluto from the prior supplement.
Wrong installment number (NúmParcialidad). The first payment is installment 1, the second is 2, and so on. A cancelled or duplicate payment can desynchronize Aspel’s counter.
Missing or incorrect exchange rate. If the invoice was in foreign currency (USD, EUR), the supplement requires the DOF exchange rate for the day of payment.
Invoice already fully paid. If prior payments already cover the full invoice amount, the SAT will reject any new supplements.

Step-by-Step Solution

Step 1 — Verify the Original Invoice Payment Method

Before generating the supplement, confirm in Aspel SAE that the income invoice has:

Payment Method: PPD
Payment Form: 99 (To be defined)

If the invoice was issued as PUE, the correct path is to cancel it and reissue it as PPD. See Aspel SAE: Error When Substituting and Reissuing a Cancelled CFDI for cancellation steps.

Step 2 — Record the Collection in Accounts Receivable

In Aspel SAE:

Go to Accounts Receivable → Collections.
Select the pending PPD invoice.
Enter the amount paid, the exact date the payment was received, and the actual payment form (03 Electronic transfer, 01 Cash, 02 Nominal check, etc.).
If payment was in foreign currency, enter the DOF exchange rate for that day.
Save the record.

Step 3 — Generate the Payment CFDI (REP)

In the collections list, select the newly recorded payment.
Click Generate Payment CFDI (button name may vary by SAE version).
Aspel will automatically populate the DoctoRelacionado node with the original invoice UUID, currency, exchange rate, installment number, and balance fields.
Review each field before proceeding to stamp.

Step 4 — Verify Critical REP Fields

Before stamping, check in the XML preview:

Field	What to Verify
UUID (DoctoRelacionado)	Matches the fiscal folio of the original invoice
NúmParcialidad	Is the next consecutive installment number
ImpSaldoAnt	Equals invoice total (1st payment) or prior REP’s ImpSaldoInsoluto
ImpPagado	Exact amount received in this payment
ImpSaldoInsoluto	ImpSaldoAnt − ImpPagado (must compute correctly)
TipoCambioP	DOF exchange rate on payment date (foreign currency only)

Step 5 — Stamp and Resolve PAC Errors

Click Stamp. If the PAC returns an error:

CFDI33102 / CFDI40194 (UUID not recognized): The original invoice fiscal folio does not exist in the SAT. Verify that the original invoice was stamped successfully and that you copied the complete UUID.
CFDI33103 (invoice already paid): Review the supplement history in Aspel. If all prior payments already cover the total, no more supplements should be issued.
CFDI40180 (wrong installment number): Check how many prior supplements exist for that invoice and adjust NúmParcialidad manually if Aspel allows it, or contact Aspel support.
PAC Timeout: Wait 5 minutes and retry. If it persists, check your internet connection and the PAC status page.

Alternative Solution

If Aspel SAE cannot generate the supplement correctly (e.g., due to corrupted historical data), you can generate it directly in the PAC web portal:

Log in to your PAC portal (e.g., Edicom, Finkok, Solucion Factible).
Select “Payment Supplement” or “REP” in the issuance menu.
Manually enter the data: UUID of the related CFDI, installment number, previous balance, amount paid, and exchange rate if applicable.
Download the stamped XML and PDF.
Import the XML into Aspel SAE’s history if your version supports it, or store it in your records.

This alternative is useful when the error originates from an Aspel bug rather than from the document data itself.

Prevention

Issue invoices as PPD from the start whenever you know payment will come later or in installments. Changing from PUE to PPD requires cancellation and reissuance.
Record collections the same day you receive payment. This ensures the correct DOF exchange rate is used and avoids confusion about previous balances.
Track supplements per invoice. Aspel SAE displays the payment history on the invoice detail screen. Review it before generating a new supplement.
Keep Aspel SAE and SAT catalogs up to date. The SAT updates catalogs for payment forms, currencies, and tax regimes. An outdated version can trigger unexpected rejections.
Do not cancel intermediate supplements without coordination. Cancelling supplement 2 (for example) will make the previous-balance fields of supplement 3 and onward mathematically inconsistent.

Payment Supplement Covering Multiple Invoices

A single REP can cover payments against multiple PPD invoices from the same client. In Aspel SAE, when recording the collection, you can associate the payment with multiple invoices. The supplement will generate one DoctoRelacionado node per invoice. Verify that the previous balances and installment numbers are correct for each one.

Error Due to Version 1.0 Supplement (Obsolete)

Since January 2022, payment supplement version 1.0 is no longer valid. If your version of Aspel SAE generates version 1.0 supplements, update immediately. Versions prior to SAE 9.0 may not support the 2.0 format.

Supplement Rejected Due to Issuer or Recipient RFC

If the issuer or recipient RFC changed (company reactivation, correction), the SAT may reject the supplement even if the UUID is valid. Ensure the RFC on the active CSD matches the issuer RFC on the original invoice.

Summary

CFDI payment supplements (REP) apply only to invoices issued with payment method PPD.
The UUID in DoctoRelacionado must exactly match the fiscal folio of the original income invoice.
ImpSaldoAnt, NúmParcialidad, and ImpSaldoInsoluto must be mathematically consistent with the full payment history.
For foreign-currency payments, use the DOF exchange rate for the day of payment.
If the PAC returns an error code, identify it in the common errors list and correct before retrying.
As a fallback, generate the supplement directly in the PAC portal if Aspel has historical data inconsistencies.