The PhD project "A Socio-semiotic Approach to Code-switching and Bigraphism in Late Antique Documentary Papyri" is part of the ERC-funded project "Everyday writing in Graeco-Roman and late antique Egypt (I – VIII AD). A socio-semiotic study of communicative variation" (EVWRIT). It focuses on multilingualism in non-literary papyri of late antiquity, with the study of primarily two multilingual phenomena attested in documentary papyri: code-switching and bigraphism. Project sources include papyrological evidence in Greek, Latin, and Coptic, drawn from the EVWRIT database. This research will be facilitated by the creation of annotation tools (e.g. character recognition tool) that will be specifically adjusted to the needs of studying the aforementioned multilingual phenomena, while respecting historical and papyrological characteristics and particularities of the texts. The general objective of this research is to relate these phenomena to their socio-historical environment, in order to obtain a better understanding of everyday multilingual communication and practices in Egyptian antiquity.