Examples are sales tickets, checks, purchase orders, bills, and bank statements.
Source documents provide objective evidence making information more reliable and useful. Source documents require analyzing a company's economic events and business transactions and recording their effects. Ultimately this includes classifying and summarizing the recorded effects in reports or financial statements. An account is a detailed record of increases and decreases in a specific asset, liability, equity, revenue or expense item. There should be a separate account for each item on the income statement and balance sheet.