Overview

• The requirement is grounded in Article 55 of the Income Tax Law and rule 3.5.13 of the Miscellaneous Fiscal Resolution, obligating banks to notify the SAT of monthly cash deposits above 15,000 pesos.
• Only cash made at teller windows or ATMs is counted toward the threshold, while electronic transfers, card payments, and checks are excluded from this trigger.
• Bank notifications can prompt SAT reviews without a prior complaint, and unexplained deposits may be treated as omitted income subject to ISR, surcharges, fines, or further legal action.
• Taxpayers are urged to register in the RFC, align declarations with actual receipts, keep contracts or receipts that prove the origin of funds, use electronic transfers when possible, and consult a tax professional.
• Separately from the monthly cash rule, individuals who receive over 600,000 pesos in loans, donations, or prizes in a year must disclose this in the annual return, and loans from companies require filing form 86-A within 15 business days.