Exchange an order item
Using the Shopify POS app, you can carry out returns and issue refunds, or exchange a returned item for a new item. If there's a difference in price between the two items, then collect or pay out the difference during the exchange.
From the Shopify POS app, tap Orders.
Tap the order for which you want to create an exchange or return.
Tap Exchange, select the item that's being exchanged, and tap Next. Returned items are added to the inventory of the assigned location for your POS device.
From the products list available, select an item to exchange your return with.
Update the quantity of the selected item, add more items if needed, and click Next.
Optional: Tap to enable Mark item as unfulfilled to note that the item needs to be sent to the customer at a later date. A new order will be created for the item(s).
If there's a balance remaining, then tap Refund or Collect and complete the transaction. If there's no balance remaining, then tap Exchange.