Cancel a stamped Mexican CFDI 4.0 invoice through the SAT portal or a PAC

Steps

1. Submit the cancellation request through either channel SAT recognizes: 'los emisores deben enviar la solicitud de cancelación de la factura a través del Portal del SAT o de los servicios [de] un proveedor de certificación' (a PAC).
2. Select the correct cancellation reason code at request time: SAT defines four codes — '01' Comprobantes emitidos con errores con relación (issued with errors, with a relation to a replacement document), '02' Comprobantes emitidos con errores sin relación (issued with errors, no relation), '03' No se llevó a cabo la operación (the operation did not take place), and '04' Operación nominativa relacionada en una factura global (a named operation related to a global invoice).
3. If the cancellation is a substitution, use reason code '01' and additionally state the folio fiscal (UUID) of the replacement CFDI, per SAT's instructions: 'se deberá señalar la clave "01"... así como manifestar el folio fiscal del comprobante que lo sustituye.'
4. Where receiver acceptance is required, expect SAT to notify the receiver through their Buzón Tributario, and expect the receiver to have 'los tres días hábiles siguientes contados a partir de la recepción de la solicitud' (three business days from receipt) to accept or reject; SAT states 'de no emitir una respuesta, se considera como una aceptación y la factura se cancela' (no response is treated as acceptance and the invoice is cancelled).
5. For cases exempt from receiver acceptance, expect immediate cancellation: SAT states 'en caso de que la solicitud de cancelación no requiera aceptación por parte del receptor, la factura se cancela de manera inmediata.'