A source document is an original document that contains the details of a business transaction. That is, it contains all the information on the goods and services bought, sold, or paid for by a business.

The most common documents are:

• Checks.
• Invoices.
• Receipts.
• Credit memos.
• Employee time cards.
• Deposit slips.
• Purchase orders.

From the options above, a cashbook is a not a source document rather, it is a book used in recording the cash transactions of a business.