The email alert for inventory, is great, but when a clerk is making a sale, they are not blocked even if the item is out. Ideally, it would be nice to have an option that states item on back order and prints that on the receipt, but just a pop-up for the clerk that says this item is low or out, so at least they can tell the customer it will be on back order. This may not be an issue for most retail shops, but we sell from the stock room as part of a set of items to be processed and picked up later. It's not fun when the customer returns to find out it's not available and has to be shipped. Most are ok with it, but sometimes they need it right away. I am realizing with this issue that I need to be sure we stay stocked up. Hopefully the email notification will be sufficient. 

Thanks for sharing your thoughts on this @hundleybk

In regards to blocking a payment of a sold out item, that's actually intentional behavior of the Point of Sale app. 

The thinking here was that if a store does not keep their quantity levels accurate (i.e. forgets to update the amount after they receive goods or a customer returns an item during business hours), we don't want to block your sales if the quantity level goes below 0 on Square, but you actually have the item in stock.

Hopefully the pop-up notification within the Point of Sale app for low-stock or out-of-stock items gains some momentum, and we can advocate to have it prioritized in the future. 

This would be great to add and to Register as well

oops, sent a reply twice. so I edited it.