That's right, if today one of your suppliers is listed as issuing false invoices, it will take all your previous purchases from deductibility and you can face fines, if you don't make your clarifications on time.

CFDI ALERT, connects and monitors your purchases daily (those of the day you can verify them before paying them), and sends you a Push Notification to your Cell, if any of your suppliers considers it as issuer of false invoices, even since it is presumed before of determining it as definitive, so that you can anticipate to present your clarifications or a case to stop buying from said supplier.