This paper analyses the nonresponse of the Integrated Survey on Living Conditions, a large continuous survey of Statistics Netherlands. For this survey, more auxiliary variables were available than in regular situations. These variables could be obtained by linking registers and databases to survey data files. Moreover, also a number of fieldwork variables were included in the analysis. By analysing the enriched survey data file, more information could be obtained about a possible under- or over-representation of certain groups in the survey.