This paper analyses respondents' behaviour when reporting their income sources in sample surveys and presents a method to deal with response error. Survey data relating to the number of earning recipients and to amounts received are validated using external information from administrative and statistical sources. Our findings suggest that the response bias on household income is about 12 per cent of reported figures. Misreporting is particularly severe for income from self-employment, financial assets and rents, as well as from secondary jobs. As to the distribution of response error, about 15 per cent of respondents show a high probability of misreporting. Misreporting is more diffuse among males, the older, the self-employed and respondents at the higher end of the earnings distribution.income distribution, response error, item response theory, SHIW, data accuracy.