A single entry system is a method of bookkeeping that records each accounting transaction with a single entry to the accounting records, rather than the more common double entry system. In a single entry system, there is only one entry made per business transaction, which is usually centered on the results of a business that are reported in the income statement. The core information tracked in a single entry system is cash disbursements and cash receipts, and asset and liability records are usually not tracked in this system.

Single entry systems are preferred for convenience, especially for small businesses with few (or no) employees that use cash basis accounting over accrual accounting, companies that have fewer financial transactions daily, and have few physical assets like buildings, equipment, and vehicles. The main advantage of a single entry system is its simplicity, which requires a minimal number of entries and low knowledge of accounting standards, making it easy for a non-accountant to use. However, the most significant problems associated with a single entry system include less information available upon reporting, making it harder to get the full picture of a companys financial standing.