The short version: some Mexican companies exist mainly to sell fake invoices for deals that never happened. Mexico's tax authority — the SAT — tracks them and publishes a public blacklist. You can check any supplier by its tax ID (in Mexico, the RFC). The catch foreign owners rarely hear about: if your business once wrote off an invoice from a company that later ends up confirmed on this list, the tax office can undo that deduction — even years afterward. The good news is that checking is quick, it's free, and catching a problem early gives you plenty of time to act.
Why checking your suppliers is worth it
The tax authority can look back 5 years
In Mexico, the SAT can review your last 5 years of accounting. So a supplier that looks perfectly fine today could be added to the blacklist next year — and the tax office can then question every invoice you wrote off from it in that window.
It doesn't matter that the supplier was on no list when you did business with it. If it later gets confirmed, the deductions you already took can be reopened. That's not meant to scare you — it's simply why a quick check today protects you down the road.
What it can cost you
- Deductions you took can be thrown out, for up to the last 5 years
- The sales tax you claimed back (Mexico's VAT) can be reversed too
- The unpaid tax comes due — with interest and fines on top
- Your business gets treated as the customer who used a fake invoice
- In serious cases, there can even be criminal exposure
The simple fix: keep an eye on the list. A supplier can land on the blacklist at any time, so a one-time check isn't enough. With EFOSGratis you can check your suppliers and clients every day, for free — and we'll tell you the moment one of them shows up, so you can sort it out long before the tax office ever asks.
What this blacklist actually is
The blacklist is Mexico's official record of companies the tax authority believes are selling invoices for transactions that never really happened. You'll hear these companies called EFOS, and the list itself called the 69-B list — but the idea behind it is simple: it's the government's public roster of fake-invoice sellers.
A company tends to land on it when the tax authority finds that it's been issuing invoices without having the means to actually do the work — no real staff, no premises, no equipment — or when the company can't even be found at its registered address. When that happens, the SAT treats the deals as fake and publishes the company on the blacklist.
Where does the list appear? In Mexico's official gazette (the DOF, the government's daily bulletin) and on the SAT's own website. And the invoices involved are the country's standard electronic invoices, known as CFDIs (Mexico's official e-invoice).
If you like, you can think of the law behind all this as Article 69-B — the rule that lets the tax authority build and publish the blacklist. But you really don't need to learn the law to stay safe (your Mexican tax advisor, or our Spanish pages, have the details). Checking your suppliers is the part that matters, and it's the easy part.
Who's who: the seller and the customer
There are really just two sides to this story. On one side is the company that issues the fake invoices — the shell company, the one that ends up on the blacklist (in Mexico, an EFOS). On the other side is the customer who used one of those invoices — and that could be a perfectly honest business like yours (in Mexico, an EDOS).
| Side | Who they are | What they do |
|---|---|---|
| The seller (EFOS) | A shell company that sells fake invoices | Issues invoices for deals that never happened — and ends up on the blacklist |
| The customer (EDOS) | The business that received one of those invoices — possibly yours | Used the invoice to lower its tax bill, often without knowing anything was wrong |
An honest business can be caught out too
Here's the part that surprises people: your business can be completely above board and still get caught simply because one supplier you paid turns out to be a fake-invoice seller. You inherit the problem without ever choosing it — which is exactly why a quick check is so worthwhile. For a friendly walk-through of the basics, see what is an EFOS.
The 4 stages a company can move through
A company doesn't just appear on the blacklist out of nowhere. Looked up by its tax ID, it can move through four stages — and knowing which stage a supplier is in tells you how worried (or relaxed) you can be:
| Stage | What it means for you |
|---|---|
| 1. Presumed | The tax authority suspects the company and has notified it, but nothing is settled yet. The company still has a chance to prove its deals were real, and for now its invoices still count. This is the early-warning stage. |
| 2. Cleared | The company proved its transactions were genuine and came off the suspect list. No problem here — you're in the clear. |
| 3. Confirmed | The company couldn't prove its deals were real, so it's now confirmed on the blacklist. Its invoices no longer count for taxes. This is the stage that causes trouble for anyone who used them. |
| 4. Cleared on appeal | The company took the matter to court and won, so the tax authority removed it from the list. Effectively, it's cleared again. |
The "confirmed" stage is the one to watch
Once a supplier is confirmed on the list, the deals behind its invoices are treated as if they never happened — and that applies looking backward, not just forward. It isn't only future invoices that stop counting; the ones you already wrote off are affected too. That's why the goal is to spot a supplier while it's still only "presumed", when you have the most time and the most options.
How to check a supplier & how we help
Checking is straightforward: you look a company up by its tax ID (RFC) against the official blacklist. Doing that once tells you where things stand today — but since a supplier can change status at any time, a single check on its own won't keep you safe for long.
That's where EFOSGratis comes in. You can check your whole list of suppliers and clients and have us watch it for you every day, for free — with two things a one-off lookup simply can't give you:
Daily monitoring and alerts
Add your list once and we'll check every company against the blacklist every day. The moment a supplier or client changes status — from clean to presumed, or from presumed to confirmed — you get an alert, so you can act in good time instead of finding out the hard way during an audit.
A dated record you can keep as proof
Every check is saved with a date. That gives you a dated record showing you checked a supplier on the day you did business with it — handy proof that you did your homework, should the tax office ever ask about a transaction.
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Add your suppliers and clients (or check just one)
Bring in your whole list at once, or look up a single company by its tax ID.
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We check them against the official list
Kept up to date with each new publication in Mexico's official gazette (the DOF).
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You see where each one stands
At a glance: who's clear, who's presumed, and who's confirmed on the blacklist.
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We keep watching, every day, for free
With an alert on any change and a dated record for your files.
If a supplier gets confirmed: you have 30 days
If a supplier of yours is confirmed on the blacklist and you'd used its invoices, you get 30 days from the date it's confirmed to either show the deal was genuine or fix your tax return. Miss both and the deduction — and the sales tax you claimed back — get reversed, with fines. So catching it early really does pay off. You'll find the full picture in risks and penalties.
A quick word: "69" and "69-B" aren't the same
If you ever hear someone mention being on a "SAT list," it's worth knowing there's more than one — and they're easy to mix up:
| The name you'll hear | What it's about |
|---|---|
| The "69" list | A separate list about unpaid or forgiven tax debts, and businesses the tax office can't locate. It's not about fake invoices. |
| The "69-B" list | The fake-invoice blacklist — the one this page is about, where shell companies (and the customers who used their invoices) show up. |
Frequently asked questions
What is the SAT 69-B list?
It's Mexico's official fake-invoice blacklist — a public list of shell companies that sell invoices for things they never actually delivered. The tax authority (the SAT) publishes it; locally these companies are called EFOS.
How do I check whether a Mexican supplier is on it?
You look the company up by its tax ID (in Mexico, the RFC). EFOSGratis lets you check your whole list of suppliers and clients and watch it every day, for free, with alerts and a dated record.
How far back can the tax authority look?
The SAT can review your last 5 years. A supplier that looks fine today could be blacklisted later, putting invoices you already wrote off at risk — which is why ongoing checking matters.
What if a supplier gets confirmed after I used its invoices?
Once it's confirmed, its invoices no longer count for taxes. As the customer, you get 30 days from that date to show the deal was real or fix your return; otherwise the deduction and the VAT you claimed are reversed, with fines.
Is checking on EFOSGratis really free?
Yes. You can check your suppliers and clients every day at no cost, with alerts and a dated record you can keep as proof. No credit card, no trial.
Where does the blacklist come from?
It comes from a Mexican tax law often called Article 69-B — the law behind the blacklist. You don't need to learn the law to stay safe (your Mexican tax advisor, or our Spanish pages, have the details). Start with the basics here.
Last updated: June 2026. This page is here to help you understand the topic — it's friendly background, not tax or legal advice. For your own situation, it's always best to check with a qualified Mexican tax advisor.