This study investigates bi- and multilingual clients' self-reported language practices in counselling and psychotherapy. Quantitative and qualitative data were collected through an international web survey inviting adults who had experienced one-to-one therapy to describe their experiences. Analysis of responses by 109 multilingual clients revealed that clients did not always have an opportunity to discuss their multilingualism with therapists, and for some this inhibited their language switching. Others were assertive in their language choices, or benefited from working with a therapist who was either bilingual or skilled at creating an inclusive linguistic environment. Very few reported two main therapy languages, while nearly two thirds of participants reported short code-switches. These happened occasionally within sessions and were typically linked to difficulties in translation, expressing emotion, accessing memories or quotation. Over a third of respondents used a second or additional language as their main therapy language, nearly half of whom reported never switching to their first language in sessions, despite some using it daily for inner speech. The implications for therapy and further research are discussed, including the role of the therapist in inviting the client's multiple languages into the therapeutic frame.