SAT guidelines on e.firma requirements and bank card usage

The Mexican Tax Administration Service (SAT) provides guidelines regarding the e.firma (electronic signature) and the risks associated with sharing bank cards.

To obtain an e.firma for the first time, individuals must schedule an appointment, present a valid official ID, CURP, proof of address, and a USB drive. The process is free, and the resulting digital certificate is valid for four years. This signature is essential for filing tax returns, requesting refunds, and accessing the Taxpayer Mailbox (Buzón Tributario).

Regarding banking, while lending a credit or debit card to others is not a fiscal crime in itself, it can trigger tax scrutiny. The SAT may investigate if account expenditures do not align with the reported income of the cardholder. To avoid fiscal discrepancy, users must be able to justify movements, ensuring that transfers from others are clearly identified as reimbursements rather than taxable income.