After a Whse Shipment is created and is being processed in the warehouse, you can still update the Transfer Order and update the shipment before it is shipped out of the warehouse.
Update Transfer Orders
When a Whse Shipment is created, only quantities allocated on the Transfer Order are copied to the Warehouse Shipment.
You may also add new items or decide to increase quantities on the transfer lines.
You cannot reduce quantities on the Transfer Lines to be less than the quantities on the Whse. Shipment Line.
Select the Pending Allocation list view to allocate inventory, especially after you receive new quantities.
By system design, one Transfer Order can only have one Whse Shipment. You will not be able to post the Whse. Shipment if there are backorder quantities on the Transfer Order.
Select the Update Shipments list view, select Transfer Orders, then click Mass Update Shipments.