These are top and recommended preorder extensions for Magento 1 & 2.

1, LandOfCoder Preorder: Magento 2 Preorder extension helps you to get sales even if your product is coming soon or out of stock and notify customers when a product gets available in the store
Link: https://landofcoder.com/magento-2-preorder-extension.html

2, Amasty Preorder: It Allow to pre-order upcoming or out of stock items
Link: https://amasty.com/pre-order-for-magento-2.html

3, Mageworx Preorder: This allows you to sell out-of-stock items as pre-orders
Link: https://www.mageworx.com/pre-orders-backorders-magento2.html

4, Aitoc Preorder: Sell forthcoming items as Pre-Orders
Link: https://www.aitoc.com/en/magento_2_pre_orders.html

If you have any questions about anything I’ve mentioned in this blog post or anything else related to Magento 2, please feel free contact me themdt@brainos.com. I am Magento Certified Developer with over 4 years experience.

MageAnts also offer magento 2 pre order extension https://www.mageants.com/pre-order-extension-for-magento-2.html

Thanks for your great post! It's really helpful.
I have a friend running a Magento store selling sportswear for wholesalers. He's considering adding Pre-order extension to allow customers to order in advance products out of stock or upcoming. He has one special note that customization ability should be real flexible as he wants to design the pre-order buttons as well as edit the notes and messages to show in the front-end. Could you recommend a suitable extension for him?
P.S: He has found this extension that meets the demand above yet not sure about its functions, do you have any suggestion?
Any help would be greatly appreciated. Thank you!

Magento 2 Missing Orders extension enables to find out the orders placed but not recorded in the Magento 2 backend and create new orders for the missing orders.


Visit: https://meetanshi.com/magento-2-missing-orders.html

Check out this [url]Magento 2 Pre Order[/https://www.milople.com/magento-2-preorder.html] Extension by Milople