The relationship between a psychotherapist and a client involves a specific kind of epistemic asymmetry: in therapy sessions the talk mainly concerns the client's experience, which is unavailable, as such, to the therapist. This epistemic asymmetry is understood in different ways within different psychotherapeutic traditions. Drawing on a corpus of 70 audio-recorded sessions of cognitive psychotherapy and psychoanalysis and using the method of conversation analysis, the interactional practices of therapists for dealing with this epistemic asymmetry are investigated. Two types of epistemic practices were found to be employed by therapists while formulating and interpreting the client's inner experience. In the formulations, the therapists and clients co-described the client's experience, demonstrating that the client's inner experience was somewhat similarly available to both participants. In the interpretations, the therapists constructed an evidential foundation for the interpretation by summarising the client's talk and using the same descriptive terms as the client. Clients held therapists accountable for this epistemic work: if they failed to engage in such work, their right to know the client's inner experience was called into question.