Abstract: A method and system for synchronizing data between a dataset and a data subset, in which filter criteria determine which data records in the dataset are excluded from the data subset. However, the filter is not applied to every record of the dataset during each synchronization. Instead, during a synchronization, the filter is applied to incoming changes received from the data subset and to outgoing changes that are intended to be sent to the data subset. Appropriate actions are taken on these changes to implement the filter parameters. When a filter is changed or newly activated, a method is performed which prepares the synchronization system so that, when the next synchronization is performed, the dataset and the data subset will automatically be synchronized according to the new filter, due to the standard application of the filter parameters during a standard synchronization.