🇲🇽 Mexico - E-Invoicing Specifications (CFDI 4.0)

Status: 🟢 Mandatory | Active for all taxpayers Authority: SAT (Servicio de Administración Tributaria) Platform: SAT Electronic Invoice System (Factura Electrónica)

1. Context & Overview

Mexico is a Latin American pioneer in e-invoicing, introducing electronic invoicing in 2004 and making it mandatory for all taxpayers since January 1, 2014. The system follows a Clearance Model requiring validation through Authorized Certification Providers (PAC). CFDI 4.0 became mandatory on April 1, 2023.

Date	Scope	Obligation
2004	CFD	Initial electronic invoicing
2011	CFDI	Internet-based system
Jan 1, 2014	All taxpayers	Mandatory e-invoicing
2017	CFDI 3.3	Major format update
Jan 1, 2022	CFDI 4.0	New version introduction
Apr 1, 2023	All taxpayers	CFDI 4.0 mandatory
Ongoing	Complementos	Additional document types

2. Technical Workflow (PAC Clearance Model)

Mexico uses a three-tier system: issuer → PAC → SAT. The PAC validates and forwards invoices to SAT.

flowchart TD
    S["Invoicerr (Supplier)"] -->|1. Generate CFDI 4.0 XML| X[XML Document]
    X -->|2. Sign with CSD| Cert[Finkit Certificate (CSD)]
    Cert -->|3. Signed XML| PAC[PAC Provider]
    
    PAC -->|4. Validate Format| V[Schema + Rules]
    V -->|5. Sign & Timestamp| PAC
    
    PAC -->|6. Submit to SAT| SAT[SAT Platform]
    SAT -->|7. Verify & Register| SAT
    
    SAT -->|8. Return XML + UUID| PAC
    PAC -->|9. Return to Issuer| S
    
    S -->|10. Deliver PDF+XML| C[Client]
    S -->|11. 3-day Delivery Window| C
    
    subgraph "Complements"
    S -.->|Pagos| CompP[CFDI Pago]
    S -.->|Nomina| CompN[CFDI Nómina]
    S -.->|IEPS| CompI[CFDI IEPS]
    end

🧱 Key Components

CSD (Certificado de Sello Digital): Digital seal certificate from SAT
PAC (Proveedor Autorizado de Certificación): Certified provider for validation
UUID (UUID/Folio Fiscal): 36-character unique identifier
CFDI 4.0: Current mandatory format
Complements: Additional documents (payments, payroll, IEPS)

3. Data Standards & Formats

A. Required Format

CFDI 4.0 XML: SAT schema
Encoding: UTF-8
Digital Signature: CSD (RSA 2048+)
PDF Delivery: Mandatory for buyers

B. Document Types

Code	Type	Description
I	Factura	Income/Invoice
E	Factura de Egreso	Refund/ Credit Note
P	Pago	Payment receipt
N	Nómina	Payroll
T	Traslado	Transfer/Waybill

C. Critical Data Fields

RFC: Tax ID (12-13 characters: 4 letters + 6 digits + 3 alphanumerics)
Nombre: Legal name
DomicilioFiscal: Fiscal address with postal code
RegimenFiscal: Tax regime code
UsoCFDI: Purpose code (G01, G03, P01, etc.)
FormaPago: Payment method code
MétodoPago: Payment method (PPD, PUE)
Moneda: Currency (MXN, USD, etc.)
TipoCambio: Exchange rate
Impuesto: Tax (002 = IVA, 003 = IEPS)
TasaOCuota: Tax rate
Importe: Line amount

4. Business Model & Compliance

A. PAC Workflow

CSD Registration: Obtain digital seal from SAT
PAC Contract: Sign with authorized provider
CFDI Generation: Create XML with all required fields
Digital Signing: Apply CSD signature
PAC Submission: Send for validation
PAC Processing: Provider signs, timestamps, forwards to SAT
SAT Registration: Authority validates and registers
UUID Return: Receive folio fiscal
Delivery: Send XML+PDF to buyer within 3 days

B. Tax Regimes

Code	Regime
601	General
605	Incorporated (RESICO)
612	Small businesses
620	Agricultural

C. Complementos (Addendas)

CFDI de Pago: Payment receipt complement
CFDI de Nómina: Payroll complement (mandatory)
IEDU: Educational institution details
Vendedor: Sales representative details
Terceros: Third-party information