How Shopify preorder actually works
Shopify handles preorder through purchase options — the same machinery behind subscriptions and Try Before You Buy. There are two deferred types: pre-order, which commits inventory and charges a deposit with the balance later, and Try Before You Buy, which ships first and charges after a set period.
The part that surprises people: you still need an app. Shopify's own documentation is blunt about it — to display information about pre-orders, you must use a pre-order app. The purchase-options framework is native; the storefront experience is not.
Once the app is configured, the product-level control sits in your admin under Products, then the product, then the purchase-option display setting — a checkbox labelled "Only display this product with these purchase options".
There is a cruder free route, which is to tick "continue selling when out of stock" and relabel the button in your theme. That takes money for stock you do not have, with no deposit logic, no deferred billing and no record that the order is a preorder. For a single drop it survives. As a system it does not.



