Abstract: A data processing system comprises a client system, comprising at least one client dataset having transactional data and customer data, a provider system, separate from the client system, and comprising an analysis engine and an action engine, wherein the analysis engine is adapted to request transactional data from the client system, on receipt of such a request, the client system is adapted to send a dataset containing transaction data linked to anonymised customer identification codes, not including customer contact information, on receipt of the dataset, the analysis engine is adapted to perform an analysis of the transaction data and generate recommendations for customer engagement in relation to at least one customer identification code within the dataset, the provider system is adapted to then request from the client system customer contact information corresponding to the at least one customer identification code and, on receipt, pass this to the action engine but not the analysis engine, and the acti