Today's corporate world is in a state of flux. The globalisation of business activity and the escalating economic crises force even small/medium enterprises to become international. This impacts on the competitiveness, profitability and survival of organisations, and as a result the companies' recruitment strategies and language policies, including the choice between global and local languages, acquire greater significance. Previous research has shown that official language policies and unofficial individual practices diverge in multifaceted ways that merit investigation. Although companies often adopt a "one language" policy, language choice is negotiated between employees in a range of contexts. Using a mixed method approach this article aims to investigate the interplay between global and local languages in the largely unexplored Greek workplace setting. In the analysis two major factors are identified which influence the choice between Greek as a local first language (L1) and English as a Lingua Franca (ELF): the official and unofficial responsibilities of employees' posts and the enactment of their professional expertise inclusive of their language competence. The analysis aims to unpack the different aspects of these themes and special attention is paid to the relevance of the current economic crisis. The paper suggests that post duties and expertise are negotiated locally and are constructed strategically to adapt to specific organisational contexts and specifically to the fallout from the economic crisis.