Dual aspect is the foundation or basic principle of accounting. It provides the very basis of recording business transactions in the books of accounts. According to this concept, every transaction has two-fold effect or has a dual impact on the accounting records.

(1) From the angle of benefit received and
(2) From the angle of benefit given. This concept is also called as duality concept. Duality principle is fundamental accounting convention and is the underlying basis for double entry book keeping system. The structure of accounting is based on this concept of duality. Accounting equation or Balance Sheet equation is also based on Dual aspect concept.

Examples:

• If business acquires asset, so decrease in some other asset. For example, purchased Furniture of ₹ 5,000 for cash.
• If business acquires asset, then increase in liability of business. For example, purchased furniture worth ₹ 5,000 from Radhe Furniture Mart.
• If business acquires asset, therefore increase in capital of owner. For example, if owner has brought personal machine of ₹ 20,000 into business.
• When goods costing ₹ 17,000 is sold for ₹ 20,000 for cash.
• When goods costing ? 12,000 is purchased on credit.
• When loan of ₹ 25,000 is received from Dena bank.
• When salary of ₹ 10,000 is paid to clerk by cash.