The Internal Revenue Service (SRI) is asking the public to report vendors who sell products illegally.

The tax agency carried out a joint operation with police and military at 93 stores all over Ecuador. Undercover shoppers found only one fifth of stores gave out receipts upon sale.

At 11 of the shops—selling car accessories, parts and cell phones—the SRI agents confiscated the seller’s stock. At some, the agents shut down the stores.

The SRI says the businesses they closed were selling used or stolen property and passing it off as new.

The practice, known as “cachinería,” needs to be reported by customers, said an SRI representative. Customers can tell when a sale is suspicious because they will not be offered a receipt.

Original story