Using claims data for research is well established. However, most claims data analyses are focused on single countries. Multi-national approaches are scarce. The application of different anonymization techniques before data are shared for research as well as differences in the reimbursement systems hamper the use of claims data from multiple countries. This paper analyses data conflicts that occur when international claims data sets are used for research and develops a generic process to detect and resolve these conflicts. The approach was successfully applied in the EU-funded ADVOCATE (Added Value for Oral Care) project that acquired data from health insurance providers, health funds or health authorities in six European countries.