Some embodiments provide a program that receives, from a first system, a copy of master data. The program also receives a master data modification rule. The program further receives, from a second system, a first request to modify a value of a second field of data in the second system with a new value. In response to the first request, the program also identifies the master data modification rule. The program further performs a set of validation operations specified in the master data modification rule. Based on the performance of the set of validation operation, the program also modifies the first field in the copy of the master data with the new value based on the supplier identifier and sends a second request to the first system to modify the first field in the master data managed by the first system.