Byo

BYO is an initialism that generally stands for "bring your own," indicating that a person supplies certain items themselves rather than relying on the host or vendor. It is also used, in some contexts, as "build your own" to describe customizable products or meals. The term is widely used in hospitality, events, and consumer services, and is distinct from BYOD, which means "bring your own device" in the technology sector.

In restaurants and bars, BYO usually refers to customers bringing alcohol or other beverages. Establishments may charge a corkage fee, restrict types or quantities, or enforce license rules. Some venues permit outside food or snacks, others do not. In other settings, BYO describes build-your-own options, such as BYO pizza, salad, or sandwich stations, where customers select ingredients themselves. Policies vary by jurisdiction and venue.

The origin of the phrase is mid- to late-20th century in English-speaking regions, evolving with changing licensing and social norms around private consumption in public venues. Today BYO appears in menus, event notices, and product marketing to signal customer-supplied components or ingredients.