Despite the success of plastic bag charges in the UK, there are still around a billion single-use plastic bags bought each year in England alone, and the government have made plans to increase the levy from 5 to 10 pence. Previous research has identified motivations for bringing personal bags to a supermarket, but little is known about the individuals who are continuing to frequently purchase single-use plastic bags after the levy. In this study, over a million loyalty card transaction records from a high-street health and beauty retailer were harnessed to study 12,968 individuals' bag buying behaviour (analysed using descriptive statistics). Statistical regional differences in plastic bag buying throughout the UK occurred. From the transaction data 2,326 frequent single-use plastic bag buyers were identified and matched randomly to infrequent buyers, creating a balanced sub-sample which was used for predictive modelling (N =4,652). For each individual in the modelling sample, their transaction data was matched to questionnaire responses measuring demographics, shopping motivations, and individual differences. Using this data, an exploratory machine learning approach was utilised to investigate the demographic and psychological predictors of frequent plastic bag consumption. It was found that frequent bag buyers spent more money in store, were younger, more likely to be male, less frugal, open to new experiences, and more displeased with their appearance (compared with infrequent bag buyers). Interestingly, environmental concerns did not predict plastic bag consumption, highlighting the disconnect between predicting pro-environmental attitudes and real world environmental behaviour.