There is both empirical and theoretical research supporting the idea that consumers' interaction with food labelling impacts on their trust in the food system and its actors. This paper explores the process by which consumers' interpretation of, and interaction with, labelling results in the formation of trust related judgements. In-depth, semi-structured interviews with 24 Australian consumers were conducted. Theoretical sampling was used to gather a wide range of consumer perspectives. Real food packages were used as prompts for discussion in interviews, with one interview section requiring participants to examine particular products while thinking aloud. Process and thematic coding were used in transcript analysis. Labelling was seen by participants as a direct and active communication with 'labellers'. The messages communicated by individual label elements were interpreted more broadly than their regulatory definitions and were integrated during the process of making sense of labelling. This enabled participants to form trust related judgements through interaction with labelling. Finally, product and consumer characteristics varied participants' judgements about the same or similar label elements and products. Divergence in consumer and regulatory interpretations of labelling creates a situation where labelling may be both fully compliant with all relevant legislation and regulation, and still be perceived as misleading by consumers. This suggests that the rational frameworks that policy seeks to overlay on consumers when considering food labelling regulation may be hindering consumer belief in the trustworthiness of labellers. Policy must recognise the different, yet equally legitimate, ways of interpreting labelling if it is to foster, and not undermine, consumer trust in the food system generally.