A pre-order and a backorder both let a customer buy a product you cannot ship yet, and the difference is timing. A pre-order sells a product before its first release, ahead of any stock existing. A backorder sells a product you already carry that is temporarily out of stock, against a future replenishment. Both create a commitment with a date attached, and both depend on the operation holding that order and fulfilling it when inventory arrives.
That is the short answer. Below is when to use each, and how fulfilling them differs.
What a pre-order is
A pre-order is a sale made before a product is available for the first time. The brand is selling ahead of stock on purpose, usually to gauge demand, fund a production run, or build anticipation for a launch. The customer knows the product is not shipping today and accepts a promised window in exchange for securing a unit.
What a backorder is
A backorder is a sale made on a product you already sell that has run out of stock, against inventory you expect to receive. The product exists and has shipped before; you have simply sold through the current supply and are letting customers keep buying rather than turning them away. For a full walkthrough of when backordering makes sense, see Backordered: What It Means and How Smart Brands Handle It.
When to use each
Use a pre-order when you are launching something new or testing demand before committing to a large run, and you want the promised date and the anticipation to be part of the story. Use a backorder when an existing product sells out and you can give an honest replenishment date, so you capture the sale instead of sending the customer to a competitor. The deciding factor in both cases is the same: whether you can quote a date you will actually hit.
How fulfillment differs
Fulfillment for the two looks similar and differs in one way that matters. A pre-order queue is usually tied to a single incoming production run or launch date, so orders convert together when that stock lands. A backorder queue is tied to ongoing replenishment, so orders convert in batches as new stock arrives over time. In both, the operation has to hold the order, keep the queue in order, allocate incoming stock to the earliest commitments first, convert to a fulfillable order automatically when inventory is received, and keep the customer informed. For how that runs during a high-demand launch, see Drops, Pre-Orders, and Backorders.
Frequently Asked Questions
The difference between a pre-order and a backorder is timing. A pre-order sells a product before its first release, ahead of any stock existing, while a backorder sells a product you already carry that is temporarily out of stock, against future replenishment. Both let a customer buy something you cannot ship yet and both depend on fulfilling the order when inventory arrives.
A pre-order is not the same as a backorder. A pre-order applies to a product that has never shipped and is being sold ahead of its launch, and a backorder applies to an existing product that has sold out and is being sold against expected new stock. The customer experience is similar, but the inventory behind each is different.
A brand should use a pre-order when launching a new product or testing demand before a production run, where the promised date and anticipation are part of the campaign. A backorder fits an existing product that has sold out, where the brand can quote an honest replenishment date and wants to capture the sale rather than lose it.
Pre-orders and backorders cause overselling when the operation cannot track committed stock accurately, because both sell against inventory that is not on the shelf yet. Avoiding it requires a real-time view of available-to-sell and a queue that allocates incoming stock to orders in the right order, so the same unit is never promised twice.
You fulfill a pre-order by holding each order with its promised ship window, keeping the pre-order queue in sequence, allocating incoming stock to the earliest orders first when the production run or launch inventory arrives, converting each held order into a fulfillable order automatically, and communicating the date to the customer along the way.
