Overview
- Mexico’s Resolución Miscelánea Fiscal 2026 postpones monetary penalties for not having an active Buzón Tributario from January 1, 2026 to 2027.
- The legal duty to enable the SAT’s digital mailbox remains in effect for RFC-registered individuals and firms, with optionality for certain exempt groups such as salaried workers under 400,000 pesos and suspended taxpayers.
- Activation requires logging in at sat.gob.mx with Contraseña or e.firma, registering at least one email and a mobile number, and confirming the contacts via emailed link or SMS code.
- Providing wrong or nonexistent contact information can be treated as opposing official notification under the Código Fiscal (articles 17‑K and 134), exposing taxpayers to administrative actions.
- Experts describe “auditorías express” that can immediately halt invoicing upon a visit order, give five business days to present proof, require a decision within 15 business days, and allow publication of RFCs or criminal referrals if false invoicing is determined.