A drop-ship line looks like any other line on the order. The difference is where the goods come from.
Before you start
The item needs a supplier marked as drop-shipping it. See Set up a product for drop shipping.
Add the line
Create or open the sales order.
Add the customer if you have not already.
Click Add dropship line — not Add line.
Search for the item and select it.
Enter the quantity and price.
Save and confirm the order.
The two buttons sit next to each other.Add line is for stock you are shipping; Add dropship line is for stock your supplier is shipping. Picking the wrong one puts the item in the wrong half of the order.
Nothing appears until a customer is attached
A brand new order shows only + Add customer. The line buttons appear once a customer is on the order — which catches people out when they go looking for the drop-ship button first.
What happens to the order
The order grows a Dropshipment tab alongside Shipment. Drop-ship lines live on one, ordinary lines on the other.
Your stock is untouched by the drop-ship line — no reservation, no change to Available. There is nothing of yours to reserve.
How to know it worked
Open the Dropshipment tab. Your line is listed with a Linked PO column showing —, meaning it has not been sent to a supplier yet. The tab tells you what comes next: "Link each item to a vendor, then create a dropshipment to have the vendor ship directly."