WMS - generate invoice from scanned WMS Picked and packed items

Currently using WMS you can scan products to generate a pick list.

If the order is being partially packed and sent we would need to split invoice to invoice the items that are packed and ready.

 It would be good it you could generate the invoice from that pick list (like how you can currently generate the pick list from the invoice). 

If not it is time consuming to do this manually from the pick and introduces a possibility of mistakes.