The widespread use of English has--for better or worse--shaped the social and communicative norms and practices of many people the world over, and the likelihood of this continuing for the foreseeable future raises questions concerning English ownership, linguistic imperialism, language attrition, and mutual intelligibility, to name a few. These themes and issues are empirically rich areas of investigation for discourse and identity studies. For example, despite its widespread use and exposure, English varies from one region to another with regard to how it is learned and used in day-to-day life and the social significance it has with families and communities. The present study investigates the identity work that takes place when interactants from different parts of the world come together and communicate in English. Specifically, this study uses membership categorization analysis to examine English as a lingua franca (ELF) encounters. Data come from a large corpus of multi-party voice-based chat rooms and the Vienna-Oxford International Corpus of English. The analysis focuses on how interactants give, and respond to, compliments concerning language proficiency. The paper aims to show how compliment sequences provide a window into how identities are co-constructed in intercultural, lingua franca encounters. Observations reveal that compliment sequences often lead to orientations of so-called "non-native" identities, and highlight the fluid and dynamic nature of discourse identity invocation and co-construction during ELF encounters.