CFDI

Comprobante Fiscal Digital por Internet — Mexico's mandatory electronic invoicing system, required for all commercial transactions by both individuals and legal entities. Every sale, purchase, payroll payment, and financial transaction in Mexico must generate a CFDI stamped (timbrado) by an authorized PAC (Proveedor Autorizado de Certificacion). Current version: CFDI 4.0 (mandatory since January 2023). Key data elements: UUID (unique 36-character identifier for each invoice), RFC of issuer and receiver (tax identification), tax regime, SAT product/service code (clave de producto — from the SAT catalog, e.g., 40161505 for V-belts), unit of measure (SAT unit code), unit price, subtotal, IVA (16% standard rate), total, payment method (PUE = single payment, PPD = partial/deferred), and CFDI use code (e.g., G03 for general expenses, I04 for equipment and machinery). CFDI must be issued within 24 hours of the transaction. For B2B industrial sales in Mexico: correct SAT product codes and CFDI compliance are essential for customers to deduct the purchase as a business expense — incorrect CFDIs cannot be deducted. Per SAT (Servicio de Administracion Tributaria) regulations and Codigo Fiscal de la Federacion.