The only way round this for me was by changing the integration we have in our wms to use the intersoft integration for royal mail.  If that isn't an option then you can use an app on Shopify to split the order (App called Split Order). to basically r...

  We have a BOGOF deal.. customer buys 2 of the same SKU and then a 3rd same SKU is added to the order as the free item..  here is the problem.. The order sales lines are added in this way; 2 x SKU 12341 x SKU 1234 Is there a way to make the system a...