Requirements for CFDI
CFDI technical operation
Pacs have different solutions for E Invoicing, that allow easy management of catalogues for customers, products and services.
One of the validations done by the PAC is the review of XML structure, to make sure it complies with the current technological standard defined by SAT.
With the certification/stamping of the PAC, the XML file is turned into a CDFI E Invoice.
Once you have a FIEL, you need to apply for a Digital Seal Certificate, CSD (for its acronym in Spanish), which is used exclusively for issuing e-Invoices in order to verify the autorship thereof (Unlike FIEL which is used also for other digital tax services).
A CSD also has a validity term of 4 years.
Look for the AMEXIPAC MEMBER SEAL:
The taxpayer, using its digital seal certificate, signs the information entered for the E Invoicing and sends the document to the PAC.
Once all validations done by PAC are completed, the PAC certifies/stamps the XML file.
The PAC then returns the CFDI Invoice to the issuer and sends a copy to SAT.