I am out of stock but I have 1,000 units inbound.
Sometimes, Amazon do this for you if you are using a partnered carrier but there is nothing you can do yourself to achieve this.
Sellers that have the capability, offer the out of stock FBA items as FBM so that sales are not missed during FBA out of stock situations.
Out of stock will lower your ranking, so start pre-sale. When the goods arrive at the Amazon warehouse, you can appropriately promote sales to reduce the customer’s purchase price, so that your goods will sell quickly.
Amazon does not allow you to sell inbound FBA units for a future delivery date unless you are eligible for their pre-order program, which is typically limited to specific categories like books and video games. However, if your inventory is already on the way to an Amazon fulfillment center, you can sometimes see a “Reserved” status, meaning customers may still purchase the item, but shipping will be delayed until the stock is received. If this isn’t the case, you could create an FBM listing with an extended handling time to take orders while waiting for your FBA stock to arrive. Another option is to run external promotions or ads to build demand so that once the inventory is available, it moves quickly.
Thanks so much for the answers. There doesn’t seem to be a way how to turn this on manually.