Hi there, PCarrington.

For now, we aren't able to give the specific time frame on when this line item discount will available in QuickBooks Online UK. 

The information provided above is the only option to create a discount item.

I suggest visiting our QuickBooks Blog to know about the latest news and updates from QuickBooks Online.

Please know that you're always welcome to post if you have any other concerns. Wishing you and your business continued success.