Stamping flow: SAT, PAC and issuers

The three actors in the fiscal cycle

The issuance of a CFDI involves three parties, each with specific responsibilities during the receipt’s certification and registration process:

Facturama → PAC → SAT

Actor	Role
Issuer	Provides the tax information for the receipt. The CFDI is signed with your Digital Seal Certificate (CSD).
PAC	It certifies the CFDI, adds the Digital Tax Stamp, and reports it to the SAT.
SAT	RRegister the CFDI as a valid tax receipt and publish the tax rules that must be followed.

The SAT

The Servicio de Administración Tributaria is Mexico’s tax authority and is responsible for establishing:

The CFDI XML standard (XSD schemas)
The valid codes for all fields (catalogs)
The validation rules for each CFDI version
The cancellation and verification processes

When issuing a CFDI, the certification and submission to the SAT are always carried out through an authorized PAC.

The PAC

The Proveedor Autorizado de Certificación is a private company accredited by the SAT to:

Validate the CFDI XML structure
Verify that the CFDI complies with current technical and tax regulations, including the validity of the issuer’s digital seal
Incorporate the Digital Tax Stamp add-on, which includes the UUID, the SAT digital seal, the PAC seal, and other certification data.
Transmit the CFDI to the SAT for registration

Facturamar. When you call the Facturama API to create a CFDI, Facturama sends the CFDI to the PAC for certification and returns the stamped XML file.

The stamping process is almost instant. The Facturama API returns the stamped XML in milliseconds. The SAT receives the report in real time.

The issuer’s CSD

To issue CFDIs, every company needs a Digital Seal Certificate (CSD), obtained from the SAT portal. The CSD is different from the e.firma (formerly FIEL). Both certificates are issued by the SAT, but they serve different purposes and are not interchangeable.

Certificate	Use
e.firma (FIEL)	Personal procedures with the SAT
CSD	Signing CFDIs

Once the CSD has been uploaded to the Facturama account, it is automatically used to sign the CFDIs issued via the API.

Full CFDI flow

1. Your system generates the CFDI JSON
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2. Your app sends the JSON to the Facturama API (POST /api/3/cfdis)
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3. Facturama generates the CFDI XML file from the received JSON and signs it using the CSD configured for the issuer
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4. Facturama validates the structure and SAT rules
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5. The PAC certifies the CFDI, assigns a UUID, and incorporates the Digital Tax Stamp
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6. The PAC reports the CFDI to the SAT and returns the certified XML file to Facturama
       ↓
7. Facturama returns the API response with the CFDI UUID, the stamped XML file, and, if applicable, the printed version in PDF format

Available environments

Facturama offers two separate environments:

Environment	Base URL	CFDIs
Sandbox	`https://apisandbox.facturama.mx`	Test — no fiscal validity
Production	`https://api.facturama.mx`	Production — Certified CFDI files are reported to the SAT and are valid for tax purposes

The credentials are different for each environment. The test CSD also differs from the production CSD.

Getting Started

Mexican Billing System

API Web

API Multiemisor

CFDI 4.0

Complements

SAT Catalogs

Tools

Stamping flow: SAT, PAC and issuers

The three actors in the fiscal cycle

The SAT

The PAC

The issuer’s CSD

Full CFDI flow

Available environments

​The three actors in the fiscal cycle

​The SAT

​The PAC

​The issuer’s CSD

​Full CFDI flow

​Available environments

The three actors in the fiscal cycle

The SAT

The PAC

The issuer’s CSD

Full CFDI flow

Available environments