Unfortunately there is no explicit function to clear a field within a workflow, but there is a workaround. It works similiar to the [Me] and [Today] trick. 1. Create a column. It does not matter how you name it or which type it is. 2. In your workflow use "Set Field in Current Item" like "Set to . 3. Save your workflow. 4. Delete the new column. Thanks to Nammy . :-)