This study investigates the dynamics of language choices among traders in Bukuru Metropolis, Jos, Plateau State, a multilingual commercial hub where Hausa, English, Nigerian Pidgin, Igbo, and Berom intersect in everyday market interactions. Anchored in Henri Tajfel and John Turner's Social Identity Theory (1979), the research examines how traders use language to express group affiliation, assert identity, negotiate status, and bridge in-group/out-group boundaries to achieve goals such as solidarity, persuasion, identity marking, and professionalism. A qualitative design was adopted, employing participant observation and oral interviews. From the diverse trading population, a purposive sample of 10 interactions was collected, encompassing provision sellers, vegetable vendors, spare-parts dealers, and phone/accessory sellers. Data were presented descriptively in tabular form and analyzed using social identity tools. Findings reveal that Nigerian Pidgin and Hausa dominate as transactional codes, with Pidgin fostering inter-group neutrality and inclusiveness, while Hausa serves as the regional lingua franca in greetings and negotiations to facilitate out-group integration. English is used strategically in contexts requiring prestige, clarity, or modernity to signal status negotiation, whereas Igbo and Berom appear in identity-driven exchanges, especially within in-group affiliation or ethnic pride contexts. The study concludes that language choice in Bukuru markets is deliberate and adaptive, reflecting the multilingual reality of Plateau State. It highlights the role of in-group/out-group strategies in sustaining peaceful coexistence and enhancing socio-economic transactions.