The rapid diffusion of smartphones and Internet use in the past few decades has led to the rise in online gambling, proliferating the opportunities for participation. Together with the recent cost-of- living crisis, it is essential that the extent of the associated harms is clearly understood. Despite the growing consensus on the need to tackle gambling harm as a public health issue, there is limited empirical knowledge on the prevalence of harm and its underlying factors. Here, we aim to reveal any geographic and social patterns of online gambling behaviour at a national scale through exploring the use of consumer data.