One-Line Definition
A backorder is an order placed for a product that is temporarily out of stock, which the seller accepts and agrees to fulfill once new inventory arrives.
In plain terms: the customer has paid (or committed to pay), the item isn't in the warehouse right now, but the order isn't cancelled — it's queued for fulfillment after the next restock.
Real-Life Analogy
Think of a popular restaurant on a Saturday night. You arrive without a reservation, and the host says, "We're fully booked right now, but if you'd like, I can put your name down — a table should open up in about 40 minutes." You're not turned away, and you're not seated immediately. You're placed in a holding pattern with a reasonable expectation of eventually getting what you came for.
A backorder works the same way. The seller is saying: *"We don't have this in stock today, but we will — and your order is locked in for when we do."* The key difference from a simple "out of stock" message is that the transaction continues rather than stops.
Core Formula
At its simplest, a backorder situation can be expressed as:
Backorder Quantity = Customer Demand − Available Inventory
When this number is positive, you have a backorder. When it's zero or negative, you can fulfill immediately from stock.
A more operational version used by fulfillment teams:
Backordered Units = Ordered Units − (On-Hand Stock + Inbound Stock Arriving Before Ship Date)
Example: A customer orders 5 units. You have 2 on hand and 1 arriving next week, but the customer needs all 5 shipped together. Backordered units = 5 − (2 + 1) = 2 units.
Backorder vs. Related Terms
Backorders are frequently confused with similar-sounding inventory states. Here's how they differ:
| Term | Customer Pays? | Order Accepted? | Fulfilled Later? | Typical Trigger |
|---|---|---|---|---|
| **Backorder** | Yes | Yes | Yes | Temporary stockout with known restock date |
| **Out of Stock (OOS)** | No | No | No (must reorder) | No inventory, no accepted order |
| **Pre-order** | Yes | Yes | Yes | Product not yet released |
| **Drop-ship** | Yes | Yes | Yes (from supplier) | Seller never holds the inventory |
| **Discontinued** | No | No | No | Product permanently removed |
The critical distinction: a backorder is a promise made after a stockout, while a pre-order is a promise made before a product exists. Both involve waiting, but only one is caused by demand outpacing supply.
Use Cases: When Backorders Make Sense
Backorders aren't inherently bad — in fact, they're a strategic tool when managed well. Common scenarios:
1. High-demand launches
A DTC brand drops a limited-edition sneaker. 3,000 units sell out in 90 minutes, but 800 more customers still want to buy. Rather than lose those sales, the brand opens a backorder window with a stated ship date 3 weeks out.
2. Supply chain delays
A cross-border seller sources from a factory in Shenzhen. A port congestion delay pushes a container back by 12 days. Instead of cancelling 400 pending orders, the seller marks them as backordered and communicates the new ETA.
3. Long-tail SKUs
A niche electronics retailer stocks 2,000 SKUs. Keeping deep inventory on every slow-mover is capital-inefficient, so it allows backorders on the bottom 15% of SKUs and restocks only when orders accumulate.
4. B2B / wholesale
A distributor orders 500 units of a component. The manufacturer has 300 ready and 200 in production. The 200 become a backorder with a scheduled delivery date.
5. Made-to-order and custom products
Personalized goods (engraved jewelry, custom furniture) are technically backordered by default — nothing ships until it's produced.
Common Misconceptions
Misconception 1: "Backorder means the order is cancelled."
No. A backorder is an *active* order. Cancellation is a separate action the customer or seller must take.
Misconception 2: "Backorder and out of stock are the same thing."
They're related but distinct. Out of stock means you *can't* buy it. Backorder means you *can* buy it, but it ships later. The customer experience is completely different.
Misconception 3: "Backorders always hurt the business."
Not true. A backorder captures revenue that would otherwise be lost, signals genuine demand (useful for forecasting), and builds anticipation for scarce products. The damage comes from *poor communication*, not from the backorder itself.
Misconception 4: "Customers hate backorders."
Customers hate *surprises*. Research consistently shows that a clearly communicated backorder with a firm ship date is far more acceptable than an order that silently sits in "processing" for weeks. According to Baymard Institute, roughly 68% of online shoppers abandon carts due to poor delivery transparency — not due to delays themselves.
Misconception 5: "Backorders are rare."
They're more common than most shoppers realize. Industry data suggests that during peak seasons (Black Friday, Lunar New Year), 20–30% of SKUs at mid-size e-commerce brands experience at least one backorder event.
Best Practices for Managing Backorders
If you're running a DTC or cross-border operation, treat backorders as a communication problem first and a logistics problem second:
- Show it upfront. Display "Ships in X days" on the product page before checkout, not after.
- Set realistic ETAs. A 10-day estimate that holds beats a 3-day estimate that slips.
- Offer a choice. Let customers wait, split the shipment, or cancel — 40%+ will choose to wait if given the option.
- Segment your inventory. Use tools like Shopify's inventory policies or NetSuite's backorder flags to automate the distinction between "in stock," "backorder," and "pre-order."
- Watch the metric. Track *backorder rate* (backordered units ÷ total ordered units). Sustained rates above 5% usually signal a forecasting or supplier problem.
Related Terms
- Out of Stock (OOS) — No inventory available; orders cannot be placed.
- Pre-order — Order placed before a product's official release date.
- Drop-shipping — Fulfillment model where the supplier ships directly to the customer.
- Allocation — Rationing limited stock across multiple pending orders.
- Fill Rate — Percentage of orders shipped complete on first attempt.
- Safety Stock — Buffer inventory held to prevent stockouts and backorders.
- Lead Time — Time between placing a replenishment order and receiving it.
- Available-to-Promise (ATP) — Inventory committed to future orders, including backorders.
Bottom line: A backorder is a controlled delay, not a failure. Handled with transparency and a credible restock date, it converts a would-be lost sale into a retained customer — and gives the seller a real-time signal about what to reorder next.