Mexico's SAT expands audits but tax revenue falls sharply in 2026

Mexico's tax authority, the Servicio de Administración Tributaria (SAT), issued a new Miscellaneous Fiscal Resolution for 2026 that updates procedural rules, including the foreign‑investment deposit factor, the base price calculation for diesel under IEPS incentives, and the removal of a rule on fiscal interest guarantees. The changes aim to clarify how taxpayers must meet obligations, prompting businesses and individuals to review the new guidelines before they take effect.

In the first quarter of 2026, SAT carried out 10,854 fiscal audits – a 37.7% year‑over‑year increase – with March alone seeing a record 3,998 massive‑scale audits, the highest monthly total in 12 years. Despite the heightened scrutiny, revenue from these audits dropped 10.96% to 212.8 billion pesos, and total tax collections fell 1.4% year‑over‑year, driven by a 5.8% decline in income‑tax receipts, the sharpest drop since 2009.