Surveys are a powerful technique in cognitive behavioural therapy (CBT). A form of behavioural experiment, surveys can be used to test beliefs, normalise symptoms and experiences, and generate compassionate perspectives. In this article, we discuss why and when to use surveys in CBT interventions for a range of psychological disorders. We also present a step-by-step guide to collaboratively designing surveys with patients, selecting the appropriate recipients, sending out surveys, discussing responses and using key learning as a part of therapy. In doing so, we hope to demonstrate that surveys are a flexible, impactful, time-efficient, individualised technique which can be readily and effectively integrated into CBT interventions.