Final answer:
The document compared to other voucher system documents to ensure correct quantity and costs, and then recorded by the accounting department, is the supplier invoice.
Step-by-step explanation:
The document being referred to in the question is the supplier invoice. This is a crucial document in the voucher system and is used to compare the internally generated documents such as purchase orders and receiving reports.
The purpose of this comparison is to ensure that the quantity and costs on the supplier invoice agree with what has been ordered and received. If the details reconcile, the accounting department will then record the purchase in the accounting records. This step is important in maintaining accurate financial statements and managing accounts payable.