The e.firma is the master key to your tax life in Mexico: with it you invoice, file returns, claim refunds and sign practically everything before the SAT. That's exactly why the SAT tightened the process to get one.
Why the change
For years, invoice mills registered shell companies at made-up addresses: an empty lot, an abandoned house, premises that never existed. With an e.firma in hand, they issued invoices for simulated operations. The result: billions in falsely credited IVA — and legitimate taxpayers paying the price with tougher reviews.
What the SAT verifies today
- That the tax address exists and can be located.
- That there's real activity: furniture, staff, visible operations.
- That the legal representative proves identity and their link to the company.
- Consistency between declared activity and the premises (a trading company in an empty apartment raises flags).
A 'not located' address doesn't just block your e.firma: it can restrict your digital seals and freeze your invoicing entirely.
How to show up prepared
Have proof of address in the company's name (or a fully compliant lease), the representative's valid ID, articles of incorporation and notarized power of attorney. Most importantly: the place should look like what you declare it to be. If you operate from home or a virtual office, check beforehand that your setup meets the SAT's requirements.
