Contemporary research, policy and guidance emphasise the importance of involving people with mental health issues in co-producing their care plans. Service user involvement in this context refers to the meaningful inclusion of individuals in decisions about their care, ensuring their experiences, values and preferences shape the services they receive. This article presents the findings of a deep dive into a dip sample of service user care plans (n=15) in a large health and social care organisation in England. The deep dive revealed that service users’ needs were rarely identified, with little correlation to outcomes. In addition, interventions mainly focused on medicines and vague therapeutic approaches, while clinical language dominated the care plans, with minimal input in the service users’ own words. The authors recommend that mental health organisations should establish a shared aspirational vision of co-production with service users and develop an understanding among staff about what a high-quality co-produced care plan should look like.