Many suppliers only take orders by case quantity or bulk packs. We then break the pack down into single units for resale. These need to be a composite to track inventory correctly because we may also sell by the case pack. 

If the distributor only recognizes the item number for a case of product and requires us to order by the case pack this means we cannot use the LW Purchase Order system. If I try to add a parent item it will add the child items instead. This will only result in generating a PO that our supplier won't understand. 

Instead of this the system should add the parent items. It can then keep note of the correct number of child items on the back end. When the PO is  delivered the system can deliver the child items just as it does now. This would allow us to send a PDF of the purchase order to our supplier. 

Currently we have to manually type item numbers and quantities into an email to place orders then we generate the PO in LW after. This would make life a little easier and prevent typos.

I was just about to start a topic on this exact thing.  This seems like a pretty vital thing to have included and makes no sense to not have this functionality active, given that you can book stock in using the parent items but you create the purchase with them.

It does render the Linnworks PO system useless for our needs too as it won't show the supplier's code / reference for the child items as we've put that in for the parent items (like they're sold from the supplier).

This would be extremely useful to have. 

We are also struggling to use PO's as it is ordering the total number of items and not the number of packs. Say I need to order 1 pack of 6, the PO will order 6 meaning my supplier will send me 6 packs of 6.