preorder
Selling an item before you can ship it: the customer buys now, you deliver once it is actually available.
See it
What it is
A preorder sells an item before you can ship it. The defining thing is availability to ship, not existence: the units might not be manufactured yet, or they might be sitting finished in a warehouse under a street date nobody is allowed to break. Two flavors, and mixing them up causes most of the pain. Charge now funds the production run but puts you on the hook for a promised date. Authorize now, charge on ship is friendlier to the customer and to consumer-protection rules, but authorizations expire, and how long you get depends on the card network, your processor, the transaction type, and whether extended authorization is supported on your account. It can be days or it can be a month, so ask your provider instead of assuming a number.
Reach for it when you want demand signal before you commit to a manufacturing run, when a launch would otherwise sell out in minutes, or when a supplier lead time leaves a gap you would rather fill with orders than with silence. Note the cousin: a backorder is the same mechanic on a product that already exists and has simply run out.
Gotcha: the ship date is a promise, and it is the only thing anyone remembers. Put it on the button, the cart line, the confirmation email, and the order status page, then email before the date slips rather than after. Also decide upfront what happens when a cart mixes in-stock and preorder items: ship it all late, or split the shipment and eat the second label.
Ask AI for it
Add preorder support to my product pages. Give each variant a preorder flag, an expected ship date, and a preorder limit that sells past zero inventory without going out of stock. On the PDP swap the add-to-cart button to 'Preorder' with a clear 'Ships by <date>' line beneath it, and repeat that date on the cart line, the checkout summary, and the confirmation email. For payment, compare the payment provider's capture window against the expected ship date and branch: use delayed capture only when the provider supports a window that covers the date (including extended authorization if available); otherwise either charge in full at order time or save the payment method with explicit, recorded customer consent for a later merchant-initiated charge. Show the shopper which one applies in plain words before they confirm, and when a cart mixes preorder and in-stock items show an explicit choice between shipping together later or splitting the shipment.