A backorder is an order placed for a product that is temporarily out of stock. The customer can still buy it — they pay now, and the order ships once inventory is replenished. When an item is backordered, it means demand has outrun available stock, but the seller expects more and is willing to keep taking orders against that incoming supply.
Backorders sit in a strange middle ground: they're simultaneously a good sign (people want your product more than you predicted) and an operational failure (you can't ship what you sold). This guide covers what backorders are, why they happen, what they actually cost, and how to run them well when you can't avoid them.
Backorder vs. Out of Stock
These get used interchangeably, but they're different commitments to the customer:
| Backorder | Out of Stock | |
|---|---|---|
| Can the customer buy it? | Yes — pays now, ships later | No — purchase disabled |
| Restock expected? | Yes, usually with a date | Unknown or none |
| Revenue | Captured immediately | Lost (or delayed to restock) |
| Customer expectation | A promised ship window | "Notify me" at best |
| Risk | Broken promises if supply slips | Customer buys elsewhere today |
The rule of thumb: backorder when you have a confirmed inbound shipment with a reliable date. Mark out of stock when you don't. A backorder without a real restock date isn't a backorder — it's a future refund request.
Why Backorders Happen
1. Demand spikes
A viral TikTok, a press mention, a competitor stockout pushing customers to you. Demand doubles overnight, and no forecast built on last quarter's data saw it coming.
2. Supplier and manufacturing delays
Your reorder was placed on time, but the factory slipped two weeks, or a raw ingredient was short. Now the gap between stockout and restock is out of your control.
3. Shipping and port delays
Inventory exists — it's just sitting on the water or in a container yard. Ocean transit variability of 1-3 weeks routinely turns a comfortable reorder into a stockout.
4. Safety stock set too low
Safety stock is the buffer between forecast error and stockout. Set it too thin to save on storage costs, and normal demand variation becomes a backorder event.
5. Inventory record errors
The system said 200 units; the shelf had 60. Miscounts, unrecorded damage, and receiving errors create phantom inventory — you keep selling units that don't exist. This one stings the most because it's fully preventable with cycle counts and an accurate WMS.
6. Reorder points that don't match lead times
If your supplier needs 45 days and your reorder point only covers 30 days of demand, you will stock out on schedule, every cycle.
What Backorders Actually Cost
The direct math looks harmless — the revenue arrives eventually. The real costs are downstream:
- Cancellations: A meaningful share of backordered customers cancel if the wait stretches past a couple of weeks — the longer the wait, the higher the cancel rate
- Support load: "Where is my order?" tickets multiply for orders that haven't shipped, each one costing support time
- Chargebacks: Card networks have delivery-window rules; orders that ship far later than promised invite disputes
- Marketplace penalties: Amazon, Walmart, and TikTok Shop track cancellation and late-ship rates — sustained backorder problems can suppress or suspend listings
- Ad waste: Paid traffic sent to a product that ships "in 3-4 weeks" converts a fraction as well while costing the same per click
- Trust erosion: First-time customers who wait weeks rarely become repeat customers
One backorder event is survivable. A pattern of them quietly caps your growth, because every marketing dollar performs worse against a product page that can't ship today.
How to Prevent Backorders
Know your real numbers
Prevention starts with three numbers per SKU: average daily sales, supplier lead time (actual, not quoted), and demand variability. Everything else is arithmetic.
Set reorder points with lead time demand + safety stock
Reorder point = (average daily sales × lead time in days) + safety stock
If you sell 40 units/day and your true lead time is 35 days, your reorder point is 1,400 units plus buffer — not "when it feels low."
Hold safety stock proportional to variability
Steady sellers need thin buffers. Products with spiky, promotion-driven demand need fat ones. A flat "two weeks of cover" across all SKUs over-stocks your slow movers and under-protects your best sellers.
Fix phantom inventory with cycle counts
Regular cycle counting keeps system inventory matched to shelf inventory. If your warehouse or 3PL doesn't cycle count, your reorder points are running on fiction. Real-time inventory visibility is one of the strongest arguments for professional e-commerce fulfillment — you can't reorder correctly on stale numbers.
Watch sell-through weekly, not monthly
Demand spikes are survivable if you catch them in week one. A weekly sell-through review per top SKU turns "we're suddenly out" into "we're trending 60% over forecast, reorder now and raise the flag."
Split inventory risk across suppliers or shipments
A second qualified supplier, or splitting one large order into two staggered shipments, converts a catastrophic delay into a partial one.
If demand has permanently outgrown your inventory operation — not just one bad month — that's usually the signal it's time to move to professional fulfillment. Our guide on when to switch to a 3PL covers the other signals.
How to Handle Backorders Well
When prevention fails, execution decides whether you keep the customer:
- Show it before checkout. "Ships by August 12" on the product page, in the cart, and at checkout. Customers accept waits they chose; they resent waits they discover.
- Give a date, not a shrug. "Backordered — ships in 2-3 weeks" massively outperforms "backordered." No date you trust? Don't take the order.
- Confirm with the timeline in writing. The order confirmation email should restate the expected ship window so support tickets don't have to.
- Update when things change. One proactive "your order is now expected on X" email prevents the ticket, the chargeback, and often the cancellation.
- Offer an exit. Easy cancellation or a swap to an in-stock alternative. Customers forced to wait cancel angrier than customers offered the choice.
- Ship backorders first the day stock lands. Your fulfillment operation should release backorders ahead of new orders on restock day — customers who waited longest ship first.
- Partial-ship multi-item orders when it makes sense. Ship the in-stock items now and the backordered item separately — eat the second-label cost for high-value orders.
That last mile is operational: on restock day, receiving needs to check inventory in fast, and the system needs to auto-release held orders. This is standard behavior in a good order fulfillment operation — pallets that land in the morning should be shipping backorders by afternoon.
Backorders and Lot-Tracked Products
For supplements, cosmetics, and food products, backorders carry an extra wrinkle: incoming replenishment arrives as new lots with new expiration dates. Your fulfillment operation needs lot tracking with FEFO rotation so that backorder releases pull correct, compliant inventory — not whatever landed nearest the dock door.
Backorder FAQ
What does backordered mean? A backordered item is temporarily out of stock but still available to purchase — the seller accepts your order and payment now and ships when inventory is replenished, usually with an estimated ship date.
How long do backorders usually take? Typically 2-4 weeks for domestically replenished products, and 4-8+ weeks when restock depends on overseas manufacturing and ocean freight. Any backorder without a stated timeframe is a warning sign.
Should I let customers buy backordered items? Yes, if you have a confirmed inbound shipment and a date you trust — you capture revenue and the customer keeps their place in line. No, if the restock date is uncertain; take email signups instead of orders you might refund.
Is a backorder the same as a pre-order? No. A pre-order is for a product that hasn't launched yet — the wait is the plan. A backorder is for an existing product that unexpectedly ran out — the wait is a failure being managed.
How do I stop getting backorders? Set reorder points from real lead times, hold safety stock sized to each SKU's demand variability, cycle count so inventory records stay accurate, and review sell-through weekly to catch demand spikes early. Most chronic backorder problems trace to stale inventory data or reorder points that ignore true lead times.
Summary
A backorder is an order taken against inventory you don't have yet — revenue captured now, shipped later. Occasional backorders are the cost of not drowning in overstock; chronic backorders are a data problem: bad reorder points, thin safety stock, phantom inventory, or all three.
Prevent what you can with accurate inventory and lead-time-based reordering. Handle the rest with honest dates, proactive updates, and same-day release when stock lands.
If your inventory visibility is the weak link — you're reordering off spreadsheets and finding out about stockouts from customers — that's fixable. Our WMS gives you real-time inventory, and our fulfillment team releases backorders the day replenishment hits the dock. Get a quote to see how it works.
