Cautions about deleting update sets Deleting an update set is a bad practice. To revert a customization, back out the update set rather than deleting it. Administrators can delete an update set only when it is not the current update set and it is empty (no sys_update_xml entries are associated with it). For example, after merging update sets, you might want to delete the original sets. This function is restricted by an access control rule (ACL) on the Update Set [sys_update_set] table. ServiceNow strongly recommends that you do not delete sys_update_xml entries, because this action: Does not undo the updates. Removes any record of who applied the customizations. Removes the sys_update_xml entries associated with the update set, so customizations are overwritten when the instance is upgraded. When you try to delete an update entry, a warning message appears. Click OK to confirm the deletion.