**Abstract**

Third-sector organisations are a collective term for voluntary and community services, charities, and social enterprises. Within the UK and internationally, a subset provides a crucial and ever-expanding role in mental health care provision, delivering valuable client and community-led services. However, in the UK these organisations are under increased pressure to demonstrate their value, and many are constrained by scarce resources and lack of expertise. The Service Improvement Learning Collaborative was conceived as an innovative model for shared learning to enhance the value of this sector in mental health care support, generating a valuable resource of practice-based learning and promoting the implementation of effective practices. The initiative combines a collaborative learning model with mentorship support and in-depth, data analytical profiling. This collaborative involved a network of six organisations focused on exploring the maximisation of data quality, the minimisation of client attrition, and the optimisation of clinical outcomes. Evaluating the collated data helped identify the many unique challenges facing the sector and evidenced the model as a pragmatic solution for service quality improvement. This chapter provides an overview of the project's methodology, including its underlying rationale, first year of operation, and value of experiential learning for the field.

**Keywords:** service quality development, collaborative learning networks, practice-based evidence, experiential learning, third-sector organisations, mental health
