How to sell inventory below zero

Allowing inventory levels to fall below zero can lead to unintended consequences, including inflated cost of goods sold (COGS) or variance account figures.

To sell an item before it’s physically in stock, create a sales order. Once you receive the inventory, convert the sales order into an invoice.

 NOTE: Sage 50 doesn’t track inventory COGS when inventory is below zero.

1. Select Setup, Settings, Inventory & Services, then Options.
2. Add a check mark next to Allow inventory levels to go below zero for items without serial numbers.
    NOTE: When there's no checkmark, you get low stock notifications. Checking the box will stop Sage 50 from sending low stock notifications. 
3. Select OK to save the setting.

Incorrect balance on the Cost of Goods Sold Expense account
How to assign a cost to an inventory item that was never purchased