Linguistic alignment has increasingly been recognised as a critical communicative resource for facilitating interaction in multilingual societies; however, empirical evidence on its commercial benefits within Nigerian informal markets remains limited. This study examined the benefits of linguistic alignment between traders and customers in Gwagwalada Main Market, Federal Capital Territory, Nigeria, through the theoretical lens of Communication Accommodation Theory (CAT). A descriptive mixed-method survey design was adopted involving 24 purposively selected participants comprising 12 traders and 12 customers equally drawn from the Hausa, Igbo and Yoruba linguistic groups. Quantitative data were generated through a structured questionnaire, while qualitative evidence was obtained through four Focus Group Discussions and ten Key Informant Interviews. The questionnaire demonstrated satisfactory internal consistency (Cronbach's α = 0.86). Quantitative data were analysed using descriptive statistics, whereas qualitative data were transcribed, coded and analysed thematically. The findings indicate that linguistic alignment constitutes a routine communicative strategy among traders, with Nigerian Pidgin and Hausa emerging as the dominant accommodation codes. Respondents identified the prevention of misunderstanding, trust building, improved negotiation, enhanced customer service, customer retention and increased business profitability as the major benefits of linguistic accommodation. The qualitative findings further revealed that shared language strengthens interpersonal trust, facilitates cultural understanding, promotes customer loyalty and enhances business expansion. These findings support the convergence principle of Communication Accommodation Theory by demonstrating that linguistic accommodation functions simultaneously as a relational and economic resource within multilingual commercial settings. The study contributes to sociolinguistic scholarship by extending empirical understanding of linguistic alignment beyond communicative effectiveness to its measurable implications for commercial sustainability in African multilingual markets. It recommends deliberate multilingual capacity development and language-sensitive business communication practices among traders operating in linguistically diverse environments.