Inventory values reduces when zero item ‘sold’ on invoice

[AngelaL10]

I've come across an issue when invoicing our new club members. I often add zero quantity of a manual which they will need at a later date, but not purchased on the day. I leave the sell price column, so they know how much it will be, and the item name to come back to later. The extended price is zero as we have sold zero quantity of the inventoried item.
 I have recently noticed our item register (when checking stock available) shows a reduction in inventory value of the item by the sales (ex gst) price, even when the inventory quantity stays the same. Why would the value of the inventory of that item reduce by the sales price (not even the correct average buy price for COS) or reduce at all when no items have actually been sold or taken from inventory ?

My inventory item remains in stock, but the value of the inventory after recording the invoice drops each time. Hence the average value of the same number of items left keeps dropping each time I record an invoice like this. 
Why would it do this ? 

[SamaraM]

Hi @AngelaL10 

Welcome to the Community Forum. Generally, we would see a change in the Cost of Sales when a purchase is entered, then later the price on the bill is changed, as the software will then do an automatic cost of sale adjustment to correct the change in price.

It sounds like this is happening in your case, but just to double-check can you provide more details on what exactly is entered the first time, and what is being edited?

If you could respond with screenshots of examples that will give me a bit of clarity on what the software is doing in the back end as well.

If my response has answered your enquiry please click "Accept as Solution" to assist other users find this information.