A back order occurs when you mistakenly sell an item that is out of stock. The dropshipper must order more inventory from the manufacturer before it will be able to fill the order for the item you have sold. This rarely makes for a happy customer. The best way to handle back orders is to avoid them. Make sure an item is in good supply before you ever place a sale on eBay to sell the item.
If you do run into a back order situation, handle the problem quickly and professionally.
Contact your customer and tell him that the item has proved to be so popular that it sold out faster than you expected. Offer to back order the item, replace it with a similar item, or refund their money immediately.
Do not try to wiggle your way out of a refund if the customer asks for one. You are the seller and it is up to you to make things right. Do so quickly, politely and professionally.
Keep in mind that your eBay feedback rating might be negatively affected if you don’t take care of the situation as quickly as possible.