Mindfulness-Based Programmes (MBPs) can help people manage long-term mental health conditions such as depression and anxiety. Bangor led the development of the Mindfulness-Based Interventions: Teaching Assessment Criteria (MBI:TAC). The MBI:TAC is the only tool that defines and assesses the elements of MBP teaching competence and fidelity for evidenced based MBPs - Mindfulness Based Cognitive Therapy (MBCT) and Mindfulness-Based Stress Reduction (MBSR). Teacher training which includes the MBI:TAC assessment leads to better outcomes (increased well-being and reductions in perceived stress) for MBP participants in mainstream settings. The freely available MBI:TAC tool is now used in 82% of MBP teacher-training organisations globally, with approximately 14,000 mindfulness teachers trained using the MBI:TAC between 2013 and 2020.