Electronic invoicing end to end: one sale, three or four CFDIs and what changed in 2026

Your company sells $11,600 (Mexican pesos), VAT included, on credit. The customer pays in two installments and, twenty days later, returns one box. A question for your next leadership meeting: how many CFDIs did your invoicing area have to issue for that single sale, of what type and by what deadline?

If the answer takes a while, that is not unusual. Electronic invoicing is learned in pieces: someone knows how to stamp invoices, someone knows how to collect, someone knows how to file. Few people see the whole cycle, and it is precisely at the joints between those pieces that money is lost: VAT the customer cannot credit, an invoice that can no longer be canceled, a fine nobody saw coming.

This article is for whoever signs off on finance, administration or operations at a company in Mexico. In nine minutes you will see:

1. What a CFDI is and what makes it valid.
2. The cycle of a sale, from the invoice to the last payment, with a worked example.
3. The most costly mistakes and what changed in 2026.

First, what a CFDI is (and what it is not)

A CFDI (Comprobante Fiscal Digital por Internet, Mexico's electronic tax invoice) is not the PDF that arrives by email. The PDF is a printed representation; the invoice is an XML file with a fixed structure defined by the SAT (Servicio de Administración Tributaria, Mexico's tax authority). For it to exist, a certification provider authorized by the SAT (PAC, proveedor autorizado de certificación) validates it, assigns it a unique tax folio (the UUID) and adds the SAT's digital seal: that is the stamp (timbre) [3]. Without the stamp there is no invoice, however good the PDF looks.

Today the version in force is CFDI 4.0, and collections on credit invoices are documented with the payment receipt complement 2.0 (complemento para recepción de pagos), which the SAT calls the electronic payment receipt (REP, recibo electrónico de pago). Both versions have been mandatory since April 1, 2023 [1][4].

A useful way to see it, if you come from IT: a CFDI is a message between companies with legal consequences. A document with a fixed schema, validated by a third party, with a unique identifier and relationships with other documents.

The cycle of a sale, in six steps

1. Issuance. Your system builds the XML with issuer, recipient, line items and taxes.
2. Stamping. The PAC validates and stamps it. This is where the invoice is rejected if the customer's RFC (Registro Federal de Contribuyentes, the taxpayer ID) is not registered, or if their name or postal code do not match that RFC in the SAT's records [1]. And if a receipt does not meet the requirements, your customer cannot deduct it or credit its VAT (IVA, value-added tax) [3].
3. Payment method. PUE (pago en una sola exhibición, payment in a single installment) when full payment has already been received at the time of invoicing, or when it was agreed to collect it in full no later than the last day of the same month and that happens; if it does not happen, the invoice must be replaced with a PPD one. If it is collected later or in installments, it goes as PPD (pago en parcialidades o diferido, installment or deferred payment) [2].
4. Payment complement (REP). Each collection on a PPD invoice is backed by a payment CFDI. One can be issued for each payment or one for all of a customer's payments in the month, no later than the fifth calendar day of the following month [2]. "The 10th" circulates online: that is not what the rule in force says.
5. Credit note. If there is later a return, a discount or a rebate, a credit-type CFDI (CFDI de egreso) is issued, related to the original invoice. The law requires it, and without supporting documents it cannot be subtracted from income [3].
6. Cancellation. If the invoice was wrong, it is corrected by replacement: first the new one is issued and then the original is canceled with reason 01. Details further on.

Worked example: one sale, three or four CFDIs

Go back to the sale from the beginning (illustrative figures): $10,000 plus $1,600 of VAT, on credit. The invoice is issued as PPD with the form of payment "to be defined" (por definir).

The numbers add up: $11,600 − $5,800 − $1,160 − $4,640 = $0. Three details separate invoicing that reconciles from invoicing that leaves loose ends:

• The second payment carries a previous balance of $4,640, not $5,800. The credit note already lowered the balance. If the complement records $5,800 as the previous balance, the invoice is left with $1,160 outstanding forever and nobody understands why it does not close. That is how the use case in the SAT's payments guide shows it [4].
• The credit note is not "paid" with a complement. It is related to the original invoice with code 01 ("credit note for the related documents"), with payment method PUE and, since the returned portion had not been collected, with the form of payment "forgiveness" (condonación): it is deducted from the balance, no money is returned [1][4].
• Three or four? Both payments come from the same customer in the same month, so they can go in a single monthly complement: that would be three CFDIs. With one complement per payment, four. Both ways are correct; what is not acceptable is for the complement not to exist.

Why the payment complement is money, not paperwork

On a PPD invoice, VAT does not become due when the invoice is issued, but when it is collected [6]. And your customer can only credit the VAT it actually paid [6]. How does it support that? With the payment complement, in addition to the bank evidence. The SAT's guide says it plainly: it is a requirement for crediting VAT and, where applicable, for deducting [4].

Seen from your customer's side: if your company does not issue the complement, that VAT is at risk of not being creditable. Your invoicing area's problem becomes a problem in the commercial relationship. The SAT even has a channel for the customer to report a supplier that does not issue it [4].

And seen from your company's side: the SAT's guide warns that failing to issue it could fall under the infraction of not issuing receipts, whose fine in 2026 ranges from $22,300 to $127,530 [3][4].

Canceling: the customer decides, and the order matters

The common idea is that canceling is an internal procedure. It is not:

• As a general rule, the customer has to accept the cancellation. They receive the notice in their Tax Mailbox (buzón tributario) and have three business days to respond; if they do not answer, they are deemed to accept [2][5].
• There are exceptions that do not require acceptance, among them: invoices of up to $1,000 (except the payment complement), credit notes, the global invoice to the general public (público en general) and invoices canceled within the business day following their issuance, with caveats such as those for fuel [2].
• An invoice with related documents in force cannot be canceled. If it already has a payment complement or a credit note, those must be canceled first [2][5]. In the example, the day 1 invoice can no longer be canceled without first undoing its related documents: the payment complements and the credit note.
• The deadline is now in the law: no later than the month in which the annual income tax (ISR, impuesto sobre la renta) return must be filed for the year in which the invoice was issued [3]. And the reason must be justified and supported [3].

The correct order to correct an invoice: first the new invoice is issued, related to the previous one as a replacement; then the original is canceled with reason 01, stating the folio of the new one [4][5]. The other way round leaves a gap: hours or days in which the sale has no valid invoice.

And a distinction that saves arguments: a credit note does not replace the cancellation of a wrong invoice. It is for returns, discounts and rebates on a transaction that did take place. If the invoice was wrong (amount, customer, product), it is canceled and replaced [5].

What changed in 2026

The reform to the Federal Tax Code (CFF, Código Fiscal de la Federación) published on November 7, 2025 brought four changes worth knowing at the leadership level [3]:

• The invoice can no longer be made conditional on the Constancia de Situación Fiscal (the SAT-issued proof of tax status). Requesting it as a requirement for invoicing is an infraction, with a fine of $21,420 to $122,440 the first time. The right thing is to ask for the data (name, RFC, postal code, tax regime), not the document.
• The invoice must cover real transactions. Otherwise, it is considered false, and the authority can act without exhausting the prior procedure.
• Issuing, selling or buying false receipts, or giving them tax effect, is a crime, with prison terms of 2 to 9 years.
• The cancellation deadline moved into the law, as we saw above. Failing to cancel in time an income invoice issued by mistake or without cause is fined at 5% to 10% of its amount [3].

As of October 16, 2026, the two amendments published to the Miscellaneous Tax Resolution (RMF, Resolución Miscelánea Fiscal) for 2026, in July and October, had not changed the rules on payments or cancellation [2].

The most costly mistakes

Five questions for your next committee

1. How many PPD invoices from this month still do not have their payment complement?
2. When a deposit comes in, who matches it to its invoice, and how long does it take?
3. How many invoices issued this year became "not cancelable" because they have related documents?
4. Does our system deduct credit notes from the balance before issuing the next complement?
5. Is anyone on our team still asking for the constancia as a condition for invoicing?

Where to start this week

Ask your invoicing area for a single report: the PPD invoices from the last quarter, with their payment complements and credit notes alongside, and the balance left on each one. The ones that do not reconcile to zero without a clear reason are the map of where the thread gets lost.

What Hábil does

Hábil makes the invoice, the payment and the bank tell the same story. Cuadre, Hábil's product for the CFDI, automatically downloads issued and received invoices from the SAT, organizes them, sends a WhatsApp alert when one arrives or is canceled, and reconciles credit invoices against their payment complements: it tells you which balances remain open and which VAT is at risk because a complement is missing. For companies that need to connect this with their ERP, their collections system or their accounting, Hábil integrates those systems without replacing them.

The first assessment conversation is at no cost: its goal is to make clear to you where your invoicing, your collections and your bank stop matching. Write to us on WhatsApp.

Sources in force as of October 16, 2026. This article is for information only and does not replace advice from your accountant.