Veeqo will allow you to accept pre-orders from BigCommerce for products that you currently have no physical stock for in your warehouse. That means your real stock of 0 is set correctly in Veeqo, but the item will still be available for purchase on your BigCommerce.
Your pre-orders will come into Veeqo as Waiting For Stock and therefore sit separately from your Ready To Ship orders, to avoid any confusion.
How to enable pre-orders on BigCommerce
1. Log into your BigCommerce Admin
2. Go to your Products page on BigCommerce Admin
3. Under the Inventory section, make sure that the Track inventory option is checkbox is unchecked
4. Click on Save