This project will involve evaluating behaviour change interventions applied to Auckland Council's food scraps collection service, to determine whether they increase participation in the service in two areas where it is currently being run in Auckland, New Zealand. This will involve running a cluster randomised trial at two locations. The interventions being evaluated include providing a free roll of food scraps caddy liners; use of social norms messaging about food scraps recycling, in a postcard sent to households; household canvassing by Auckland Council WasteWise Advisors; and a sticker prompt, affixed to households’ refuse bins, discouraging people from putting food scraps into the bin. The outcome variables we are interested in are observed participation and set-out. The two trials will take place simultaneously and the study will run across a four-month period.