Written for Mexico. This analysis applies to Mexican federal tax law — ISR (income tax), IVA (VAT) and SAT rules — and cites Mexican statutes. Amounts are in Mexican pesos (MXN).
Most people picture the SAT as their only observer. In reality a triangle is at work: the UIF (the Treasury's financial intelligence unit), the SAT (tax enforcement) and the FGR (criminal prosecution) — three institutions with different mandates, connected databases, and joint-action protocols that are triggered more often every year. Understanding who sees what, who can do what, and when they hand off the baton is understanding the full risk board.
What each vertex sees
The UIF concentrates the reports from the financial system: relevant operations (cash above thresholds on the order of thousands of dollars — moderate confidence on the exact current cut-off), unusual ones (those that don't match your transactional profile, with no threshold: here the bank's algorithm and compliance officer rule) and concerning ones, plus the vulnerable-activity reports filed by notaries, real-estate agents, lenders and the other parties obligated under the Anti-Money-Laundering Law. The UIF neither collects taxes nor prosecutes: it analyzes and disseminates — and it has a feared administrative tool: the Blocked Persons List, the freezing of accounts without prior trial (narrowed by the courts, in consolidated criteria, mainly to cases with an international link — moderate-to-high confidence; in practice it is still used and unblocking is litigated).
The SAT sees your tax universe: CFDIs (digital tax invoices) in real time, returns, electronic accounting, foreign trade, and the financial information it receives by law — deposits, interest (and the global balances that arrive from abroad via CRS/FATCA). Its weapons: audits, 69-B, restriction of digital seals (CSD), seizures. The FGR — with its unit specialized in tax and financial crimes — steps in when there is a crime to prosecute: it receives the criminal complaints from the SHCP (Treasury) in fraud cases, the UIF's referrals in money laundering, and takes them to court.
The bridges: what they share and how
Tax secrecy and bank secrecy have express exceptions among themselves: the CFF lets the SAT share with authorities, and the UIF accesses tax and financial information in its analyses; there are collaboration and systematic-exchange agreements among the three, plus joint task forces for major cases (the offensive against invoice mills was built exactly this way: the SAT detects the network through CFDIs, the UIF maps the flows and freezes them, the FGR takes it to court). The practical translation: what one sees, the system can see — the notary's anti-laundering report, the bank's unusual-operation report and your annual return are pieces of the same puzzle when someone decides to assemble it. The discrepancy between your bank flows and your tax profile no longer needs an auditor to find it: the cross-checks produce it.
When they act together — the typical ladder
The purely administrative case (a rejected deduction) lives and dies at the SAT. The ladder is triggered by patterns: invoicing without substance (69-B → complaint → criminal file → UIF freezing of the entire network, clients included in some scenarios), simulated-payroll schemes, international flows with no support, and cash structures. The most important signal for the legitimate business owner: in the world of the triangle, the defense is the file, not discretion — the three vertices see regardless; what decides your fate is whether every flow, contract and transaction has its documented story (substance, fecha cierta / verifiable date, demonstrable lawful origin) before anyone asks.
Would your flows withstand all three reading them at once?
The traceability diagnostic reviews your operation as the triangle would see it: consistency among CFDIs, banks and returns; transactional profile vs. tax profile; the anti-laundering exposure of your activities; and the origin files for your large wealth movements. It's the same exercise the authority runs — with the difference that, done in time, every finding is fixable.
Frequently asked questions
Does my bank tell the SAT about my transactions?
The bank reports to the UIF (relevant/unusual operations) and hands the SAT information such as cash deposits and interest by legal mandate, on top of answering requests during audit powers. There is no real-time mirror of your account to the SAT — but the combination of reports, cross-checks and CRS produces enough visibility to detect any structural inconsistency.
My accounts were frozen under the Blocked Persons List — what do I do?
This is a matter of days: you request the unblocking before the UIF itself (with a guarantee hearing) and file an amparo (constitutional injunction) in parallel — the courts have narrowed the domestic use of the list and there are solid unblocking precedents. Speed and documenting the lawful origin of the funds decide the case; operating for weeks with your treasury frozen is the real damage.
Do anonymous tips activate this triangle?
Reporting channels exist and they do generate files, but the system's real engine is data: automatic cross-checks produce more cases than tips do. The uncomfortable and useful corollary: your main potential accuser is your own inconsistent information.
Let's talk about your case
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