Public health physical activity (PA) guidelines are failing to increase levels of population PA, requiring a new approach. A national integrated marketing campaign was developed based on published literature and ethnographic research to get inactive lower socioeconomic 40-60 year olds to walk briskly for bouts of 10 or more minutes per day and move towards recommended levels of PA. National and local communications campaigns and partnerships promoted key messages and directed people to a free mobile phone app that provided the user with time, intensity and periodicity of walking, and included goal setting and encouragement to support behaviour change. Campaigns in the summers of 2017 and 2018 achieved around 500,000 downloads of the mobile phone app, with evaluation suggesting increases in brand and app awareness, and those taking action. Active 10 is a promising example of a physical activity promotion campaign based on evidence-based messages tailored for a target audience to change social norms rather than guidelines, an approach recognised as an effective population intervention for increasing walking.