Researchers seeking to perform country‐comparative and trend analyses using income data have to account for the fact that income surveys differ in whether income is measured gross or net of taxes and contributions. We discuss, develop, and evaluate two ‘netting down procedures’ for data in the LIS Database. Evaluations of these netting down procedures indicate that comparisons across gross and net datasets can be greatly improved when netting down procedures are applied. In several cases, however, substantial amounts of bias remain.