Methodological studies examining the veracity of sexual behaviour reports frequently focus on the source of unreliable, inaccurate or inconsistent responses. This paper, instead, explores the means by which respondents might be assisted in providing an accurate account of their sexual experience. We present findings from a survey development study (second Great Britain National Survey of Sexual Attitudes and Lifestyles, development phase), which used in-depth interviews to explore respondents' experiences of completing a pilot survey of sexual behaviour. Follow up interviews were conducted across the UK with 36 of the pilot survey sample (n = 897). We explored factors that aided reliable reporting in each research format (survey and in-depth interview), as well as factors facilitating consistent reporting across formats. We show that factors such as assurances of confidentiality, survey legitimacy, rapport between interviewer and respondent and perceptions of the therapeutic benefit of disclosure can assist accurate disclosure across both survey and in-depth interview. We draw upon the strengths of qualitative methodology to make recommendations for future survey research.