An Expense Verification System (EVS) checks for fraud and errors in reimbursement requests. The EVS stores requests including reference numbers, and receives travel reservation records from a payment clearinghouse system. Each record includes a reference number and associated reservation data. The EVS selectively denies stored reimbursement requests as a function of data contained in the travel reservation record. Alternatively, the EVS selectively issues an alert as a function of data contained in the travel reservation record. Further, the EVS may parse a received reimbursement request to identify a respective reference number, compare the parsed reference number to the stored reimbursement requests to determine whether the parsed reference number matches a stored reference number, and deny the received reimbursement request if the parsed reference number matches a stored reference number. The EVS may store the received reimbursement request if the parsed reference number does not match a stored reference number.