Tax paperwork becomes easier to navigate when you ask what each item proves. Some identify a taxpayer, some authorize a digital action, and others record a transaction or a submission. One document does not replace another.

Identity and current registration

The RFC identifies a registered taxpayer. A Constancia de Situación Fiscal describes the SAT registration data, including the RFC, name, registered address, and fiscal regime. It is a snapshot of registered facts, not proof that every return or payment is complete. The SAT Constancia page explains its contents and retrieval routes.

Signing material

An e.firma is a personal electronic signing credential. Treat its private key and password like sensitive credentials: retain them in secure private storage, do not send them by chat, and do not upload them to Conteo. A certificate of digital seal (CSD) has a different invoicing role; ask SAT or your adviser which credential a specific action requires. See the SAT e.firma procedure and CSD request.

Transaction and submission evidence

A CFDI XML is the electronic tax document. Keep the original XML and, when useful for reading, its printed or PDF representation. The SAT CFDI recovery service provides a way to retrieve issued or received XML. Keep any cancellation or replacement trail with the related invoice.

An acknowledgment records a submitted action; it is not the same as the underlying CFDI or a bank payment. Preserve the actual document and its identifying details privately. For RFC acknowledgments, the SAT reprint service is an official starting point for filings made from April 2014 onward. For a declaration, separately verify any payment obligation and retain payment evidence; SAT distinguishes the declaration acknowledgment and bank receipt.

A practical private folder

  • Keep registration documents, signing materials, CFDI XML, and acknowledgments in separate access-controlled locations.
  • Name files with the relevant period or transaction so an adviser can trace them, without exposing RFCs or credentials in public links.
  • When correcting a record, preserve the original and the correction relationship.

This map is orientation only. Confirm your specific obligations with SAT and a qualified adviser.