The Medicines and Healthcare products Regulatory Agency (MHRA) has issued new guidance to help manufacturers navigate UK medical device regulations for digital mental health technologies (DMHTs). The guidance, an output from a three-year Wellcome-funded project launched in 2023, explains how to define the intended purpose of DMHTs, when they are considered medical devices, and how risk classification is determined. MHRA has developed this guidance with input from NICE, NHS experts, researchers, healthcare professionals, and people with lived experience to address the growing mental health crisis in the UK. The guidance aims to ensure DMHTs are effective, reliable, and acceptably safe, while providing greater confidence to users of mental health apps and supporting safe access to these tools.