The aim of this research was to examine the influence of a UK national retailer on its customers' food waste behaviour. Using six communication channels (in‐store magazine, e‐newsletter, Facebook site, product stickers and in‐store demonstrations), Asda presented standard food waste reduction messages to its customers during two time limited periods in 2014 and 2015. Six national surveys over 21 months tracked customers' self‐reported food waste. Our results showed that the combined communication channels and repeated messages over time had a significant effect on reducing food waste of customers. Surprisingly, customers who said they did not recall seeing the messages also reduced their food waste, showing the wider influence of interventions. Those who saw a food waste reduction message saved an estimated £81 annually from reducing food waste. The main conclusion of this paper is that retailers can influence the pro‐environmental behaviour of customers using conventional communication channels; however, repeat messages are needed in order to have a long‐term impact. © 2017 The Authors. Business Strategy and the Environment published by ERP Environment and John Wiley & Sons Ltd