An abbreviation for business-to-business which indicates an offline or online marketing activity involving the exchange of products, services, or information between businesses (firms) as opposed to marketing by businesses directly to consumers, i.e., business-to-consumer (B2C) or vice versa, i.e. consumer-to-business (C2B).

For example, a B2B transaction may involve a wholesale bank selling services to a retaining bank such as payment facilities, finance wholesaling, underwriting, market making, mergers and acquisitions, fund management, etc. The term is usually associated with, but not limited to, e-commerce.