Business-to-business (B2B) refers to a situation where one business makes a commercial transaction with another. This typically occurs when:

• A business is sourcing materials for their production process, e.g. a food manufacturer purchasing salt
• A business needs the services of another for operational reasons, e.g. a food manufacturer employing an accountancy firm to audit their finances
• A business re-sells goods and services produced by others, e.g. a retailer buying the end product from the food manufacturer

Contrasting terms are business-to-consumer (B2C) and business-to-government (B2G). B2B branding is a term used in marketing.

The overall volume of B2B (Business-to-Business) transactions is much higher than the volume of B2C transactions. The primary reason for this is that in a typical supply chain there will be many B2B transactions involving sub components or raw materials, and only one B2C transaction, specifically sale of the finished product to the end customer.