A Tax Administration Service (SAT) audit can generate tax assessments that threaten the continuity of a business. Knowing the types of review and the appropriate defense strategy can significantly reduce the impact.
The Three Types of SAT Audits
- On-site audit (visita domiciliaria): SAT auditors physically visit the company's registered address. The most comprehensive type and the one that causes the greatest operational uncertainty.
- Desk review (revisión de gabinete): SAT requests information and documentation in writing. The company has deadlines to submit documents without auditors visiting the premises.
- Electronic review (revisión electrónica): SAT detects discrepancies in electronic data (CFDI invoices, tax returns, DIOT reports) and notifies the taxpayer directly through their tax mailbox. The taxpayer has 15 days to rebut the discrepancies.
Deadlines You Cannot Ignore
In a desk review, the taxpayer has 15 business days to submit the requested information (extendable once by 10 additional days). In an electronic review, the deadline is 15 days with no automatic extension. Failing to respond on time may result in the provisional tax assessment becoming final with no opportunity for clarification.
Documents SAT Always Requests
Regardless of the audit type, always prepare:
- Accounting journal entries for the reviewed period
- Income documentation (CFDI invoices issued)
- Deduction documentation (CFDI invoices received with evidence of economic substance)
- Bank statements
- Reconciliation between the annual tax return and accounting records
- Contracts supporting the most significant income and expenses
Available Challenge Mechanisms
If SAT issues a tax assessment you believe is incorrect, you have three main options:
- Revocation appeal (recurso de revocación): filed with the same authority. Deadline: 30 business days. Resolution: 3 to 6 months.
- Administrative litigation: before the Federal Court of Administrative Justice. Takes longer but offers more procedural options.
- Indirect amparo (judicial review): in cases where the act violates constitutional guarantees.