Accounting documents are the official records of all financial transactions in an accounting system. They include invoices, purchase orders, bank statements, and reports that document the movement of money within a business entity. They provide a record of all income and expenses, and serve to protect a company from fraud and errors. Furthermore, they facilitate the ability to determine taxes due and other obligations that must be paid by a company or person. Accounting documents are essential to any business and should be treated with utmost care.