Many Intermediaries

"After a transaction is authorized, the merchant submits receipts to its acquiring bank, which requests reimbursement from the issuing bank through an automatic clearinghouse network. The issuing bank also analyzes the transaction for fraud, comparing it with the customer's usual purchasing patterns and contacting the customer when activity appears suspicious. Once the transaction is approved, the bank debits the customer's account and the acquiring bank credits the merchant, a process that can take up to three business days."