Solution let cusTask = task.create({ taskType: task.TaskType.ENTITY_DEDUPLICATION }) cusTask.entityType = task.DedupeEntityType.CUSTOMER; cusTask.dedupeMode = task.DedupeMode.MAKE_MASTER_PARENT; cusTask.masterSelectionMode = task.MasterSelectionMode.SELECT_BY_ID cusTask.masterRecordId = ‘112255’ //master record ID cusTask.recordIds = [‘2255′,’66332’] // internal ids of duplicates Or to merge based on recent activity, use, cusTask.masterSelectionMode = task.MasterSelectionMode.MOST_RECENT_ACTIVITY cusTask.recordIds = [‘112255′,’2255′,’66332’]; // provide internal id of all records. NetSuite will find… Continue reading Merge duplicate customer as Subcustomer through N/task