Over the past several decades, English as a Lingua Franca (ELF) has become a major field of linguistic interest. The majority of ELF-related research to date has focused on its lexical and grammatical features. However, recent work (e.g. Kecskes 2013) has increasingly turned to explore the pragmatic aspects of ELF, and this paper aims to contribute to this emerging area of research by presenting a contrastive study of ELF and L1 English discourse. The study focuses on one specific genre - restaurant-owners' responses to negative customer reviews on the TripAdvisor website - and compares a corpus of ELF responses (posted by restaurants in Prague) with a comparable corpus of L1 English responses (restaurants in the UK). The analysis is anchored in an interactional-pragmatic framework informed by the concepts of facework (Goffman 1967), rapport management (Spencer-Oatey 2000, 2002, 2007, 2008) and relational work (Locher & Watts 2005, 2008). Negative customer reviews posted on TripAdvisor represent face-threatening acts which endanger the business's institutional face, but the restaurant-owners' responses offer an opportunity for both face-saving and rapport-building (relational work); to maximize these potential benefits, respondents must strike a balance between their own face needs and those of the complainant. Applying a combination of qualitative and quantitative analytical methods, the contrastive study presented in this paper explores key differences and similarities between the facework and relational work practices used by ELF and L1 respondents.