CFDI basics: Mexico's electronic invoice for foreign teams

How a CFDI comes to exist

Issuing a CFDI takes four steps, usually automated by your invoicing software:

1. Prepare. Your system builds the XML with issuer, receiver, items, taxes and payment terms.
2. Sign. The issuer signs it with its digital seal certificate (CSD), issued by the SAT.
3. Stamp. An authorised certification provider (PAC, Proveedor Autorizado de Certificación) validates it and adds the timbre fiscal, including a UUID, the unique folio fiscal.
4. Deliver. You send the XML and a PDF to the customer. The SAT already has a copy.

Only after stamping does the invoice legally exist. A draft in your ERP is not a CFDI.

The CFDI types an AR team meets

Type	Spanish	Used for
I	Ingreso	Sales invoices
E	Egreso	Credit notes, discounts, returns
P	Pago	Payment receipts (complemento de pago)
T	Traslado	Goods in transit
N	Nómina	Payroll

Collections teams work mostly with I, E and P. A type P document is the payment receipt described in the complemento de pago guide.

Fields worth knowing on an income invoice

• RFC. The Mexican tax ID of issuer and receiver.
• Receiver's name, postal code and tax regime. Version 4.0 requires these to match the SAT's records exactly; mismatches are a common rejection reason.
• Uso del CFDI. How the receiver will use the invoice for tax purposes.
• Método de pago. PUE (paid at once) or PPD (paid later or in instalments), explained in PUE vs PPD explained.
• Forma de pago. How payment was made, such as transfer or cash, or 99 "to be defined" for PPD.
• Currency and exchange rate, if not in pesos.
• Taxes, typically IVA (VAT) and any withholdings.

Validating a CFDI you received

The SAT runs a public verification service where you enter the UUID, issuer RFC, receiver RFC and total to confirm a CFDI is valid and not cancelled. Accounts payable teams should run this check on supplier invoices. AR teams use the same check when a customer claims an invoice was cancelled.

Keeping CFDI files where you can find them

Every Mexican entity should keep the XML of each CFDI it issues and receives, organised by month and by counterparty. The SAT's portal lets you download issued and received invoices in bulk, which is a useful completeness check against your ERP. Shared-service centres often run that comparison monthly: any invoice in the SAT download that is missing from the ERP, or the reverse, needs an explanation before the close.

Cancellation and replacement at a high level

A stamped CFDI cannot be edited. To fix it, you cancel it with a reason code and, where relevant, issue a replacement that references the original. Some cancellations need the receiver to accept them. The rules and time limits change from time to time, so check them with your accountant before you cancel.

Situation	Usual fix
Wrong receiver data	Cancel and replace
Wrong amount, not yet paid	Cancel and replace
Partial return after payment	Issue a credit note (type E)
Wrong payment method code	Cancel and replace, then follow PPD rules

How CFDIs connect to bank deposits

An invoice says what is owed. The bank statement says what arrived. In Mexico, the payment receipt makes the link explicit for the SAT. An illustrative chain: invoice A-500 for 30,000 MXN issued as PPD on 2 October, a SPEI transfer of 30,000 MXN received on 28 October, and a payment receipt dated 28 October that references A-500's UUID with a remaining balance of zero.

When any of the three is missing or disagrees, the month-end review flags it.

Getting the deposit side right with Meses

The CFDI side is usually handled by your invoicing provider. The bank side, deciding which deposit pays which invoice, is where Meses (meses.ai) helps. Meses is the AI platform for collections reconciliation in Latin America: it matches bank-statement deposits to what customers owe (dues, tuition, rent, instalments or invoices) and updates your records in minutes. Pricing is shared during onboarding.