Objective: Psychological interventions reduce the impact of psychosis, but widescale implementation is problematic. We tested the feasibility of group acceptance and commitment therapy for Psychosis (G‐ACTp), delivered by frontline staff, and co‐facilitated by service‐user experts‐by‐experience (SU‐EbyE), for service‐users and informal caregivers (ISRCTN: 68540929). We estimated recruitment/retention rates and outcome variability for future evaluation.