Mexico's CFDI 4.0 standard is the mandatory electronic invoice format issued by the SAT. OMB Cloud handles the full flow — generation, validation, stamping (timbrado) and delivery.
One-time setup
- Get your CSD (Certificado de Sello Digital) from the SAT portal — separate from the FIEL, used only for invoicing.
- In
/app/master-billing→ your MX entity → "CFDI settings", upload the.cerfile, the.keyfile, and enter the key password. - Set default values: RFC, Regimen Fiscal, Lugar de Expedicion (CP), default Forma de Pago and Metodo de Pago.
The issuance flow
When you click "Issue invoice", OMB Cloud: (1) generates the CFDI XML from your line items; (2) signs it with your CSD; (3) routes to the multi-emisor wholesale timbrado service; (4) receives the timbre fiscal and folio; (5) generates the stamped XML and printable PDF; (6) delivers both to the client by email.
Cancellations
To cancel a CFDI: open the invoice → "Cancel" → choose the cancellation reason (01 errors with relation, 02 no relation, 03 no operation, 04 nominative). For 01 cancellations, OMB Cloud auto-creates the substitution CFDI linked via UUID.
Credit notes
For partial reversals (returns, discounts), use Credit Note instead of cancellation. The credit note references the original CFDI and reduces the receivable correspondingly.
Tips
- The default Forma de Pago (PUE) and Metodo de Pago (efectivo, transferencia) per client saves clicks. Set them in the client record once.
- Currency: most MX invoices are in MXN, but USD-denominated invoices are valid with proper FX disclosure.
- The UI never displays the PAC vendor name — wholesale timbrado is bundled in your OMB Cloud plan.