Running a company in Mexico? Here's a local risk most foreign owners never hear about — and the good news is it's easy to stay ahead of. Some Mexican companies exist mainly to sell fake invoices for deals that never happened — "shell companies" the tax authority puts on a public blacklist. If your business ever wrote off an invoice from one of them, the tax office can cancel that deduction, demand the back taxes, and add fines. Checking your suppliers and clients takes just a few minutes — and it's completely free.
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14,521 RFCs from the SAT 69-B and 49 Bis lists · updated Oct 6, 2026
In Mexico, some companies are set up mainly to sell invoices for goods or services they never actually delivered. The tax authority catches them and adds them to an official blacklist. Locally these companies are called EFOS — but the part that matters is simpler: the tax penalty usually falls on the customer who used the invoice. If that's your company, a deduction you took can be thrown out years later.
The trap most foreign businesses fall into: you can do everything right — pay a supplier that looks completely legitimate, receive a normal invoice, and deduct it like any other expense — and still get caught. If that supplier is flagged later, the problem becomes yours: the tax office can reach back several years and undo the deduction, and you usually only find out during an audit, with little time to react. The reassuring part — a quick check today, plus ongoing monitoring, keeps you clear of it.
A "shell company" that issues invoices for deals that never happened. Mexico blacklists them (locally: EFOS).
Whoever wrote off that invoice. In Mexico this side is called an EDOS — and it's who the tax office comes after.
An official, public list. The dangerous moment is when a supplier is confirmed on it — their invoices stop counting for taxes.
Lost deductions, back taxes with interest, fines that can exceed half the amount — and, in serious cases, criminal exposure.
Just your email. No credit card.
Inside iAudita, connect your company's Mexican e-signature once. That's how we read your invoices straight from the SAT.
Every supplier and client in your invoices checked against the blacklist, with how much each one billed you. The check refreshes every day.
Coming soon: upload a list of RFCs without the e-signature. Join the waitlist in the RFC check above.
In some foreign-owned companies, someone on the local team buys invoices from an invoice mill —an EFOS— and books them as supplier expenses to take money out of the company. From abroad they look like ordinary operations: a supplier, an invoice, a payment.
It surfaces when the SAT lists the issuer: the company finds 100 or even 1,000 invoices from a supplier that never delivered anything, and the SAT can reject those deductions going back 5 years.
Checking every supplier against the list, and seeing how much each one billed you, is how you catch it early.
The EFOS check is just the start. With iAudita you connect your company's e.firma once and see, straight from the SAT, what it invoices and collects, whether its taxes are filed and paid, and where it stands with the tax authority. No reports to request from your accountant or your team — and the platform works in English and Chinese, not just Spanish.
What your company invoices, what has been collected and what is still pending, based on the invoices (CFDI) registered with the SAT.
Your 5-year filing record at a glance: every monthly and annual return filed under your company's RFC, downloaded from the SAT, and which ones are still missing.
Each return with its SAT payment receipt, so you know the tax was paid, not just declared.
We compare the VAT and income tax your accountant declared with what your invoices say, and flag the differences.
Your tax compliance opinion (32-D), positive or negative, and the letters and requirements the SAT sends to your company's tax mailbox — before a deadline runs out.
The EFOS check on every supplier and client in your invoices, updated every day against the SAT list.
A short walkthrough in English with our team. Or learn more about iAudita.
Your free account includes the EFOS check. When you connect your company's e.firma, you can try the full platform free for 7 days.
We're iAudita, a Mexican tax-compliance platform. This free check is how foreign-owned companies and their accountants get to know us. Checking your business partners is yours, free, for good.
We compare against Mexico's official government blacklist, kept up to date.
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