Lifetime prevalence in victimisation studies tends to be estimated through reported answers to survey questions, by asking respondents whether an event such as intimate violence has ever happened in their lives up to that point. For example, in the WHO multi-country study of women’s health and domestic violence, the lifetime prevalence of partner violence was defined as “the proportion of ever-partnered women who reported having experienced one or more acts of physical or sexual violence by a current or former partner at any point in their lives”(Garcia-Moreno et al, 2006) This definition ignores any event which might take place in the lives of the respondents. Under this definition, the lifetime prevalence will vary by the age of the respondent , and will not be an estimate of the risk of victimisation over the whole life of the respondent. Taking the example of intimate violence in England and Wales, and using the British Crime Survey, we discuss the issues involved in making an estimate of true lifetime prevalence from survey data including recall, underreporting and missingness. Finally we present methodology which addresses this problem through a statistical modelling approach, and presents initial estimates for true lifetime prevalence of intimate violence.