$1.$ The company issues sales invoices in sequential order. Use the Invoice file to determine whether there are any gaps or duplicates in the sales invoice sequence.

$2.$ Company policy is that invoices are prepared after the invoicing function receives notification of shipment to the customer. Verify that each shipment in the Bills of Lading file is associated with an invoice in the Invoice file.

$3.$ Company policy is that invoices should be prepared within five days of shipment. Identify any sales included in the Invoice file that were not invoiced within five days of shipment.

$4.$ Verify that all sales included in the Invoice file are to authorized customers included in the Customer List file.

$5.$ Verify that the quantity and product number billed on the sales invoice matches the same information on the bill of lading and sales order $($three$-$way match using the Invoice, Bill of Lading, and Sales Order files$).($Hint$!!$ List the Invoice numbers for instances where the Quantity per the Sales Order file differs from the Quantity per the Invoice file, and list the Invoice numbers for instances where the Quantity per the Bill of Lading file differs from the Quantity per the Invoice file$)$

$6.$ Determine that the total amount of the invoices included in the Invoice file $($in the Amount column$)$ is properly computed based on the quantities shipped and invoice prices.