There are a few reasons why casinos request identification when players cash out their winnings. Firstly, it helps comply with the "know your customer" directives in which casinos are required to collect a certain type of information about all players to confirm their age and review suspicious or possibly fraudulent activity. Casinos, by ing the identities of players, make sure that the transactions are transparent, and aboveboard, and the clients are of the right legal age. The second reason is with regard to AML, where it is, in fact, bound by law that casinos a customer's identity for the purpose of deterring money laundering and all other financial crimes related to it. Although frustrating at times for players, these checks are important in making sure there is a safe gaming environment that protects the casino and its patrons.