Backorders in Retail: How to Sell What You Don't Have Yet Without Losing Track

A backorder is a sale you accept for an item you don't have on the shelf right now, with a promise to fill it once new stock arrives. Handling backorders well comes down to four things: never letting your on-hand number pretend you have stock you don't, tracking exactly how many units are "owed" to customers separately from what's actually available to sell, deciding upfront whether an out-of-stock item gets hidden or offered as a backorder on your online store, and turning the shortfall into a purchase order fast enough that customers aren't waiting on a promise you haven't acted on.

What Is a Backorder, and How Is It Different From Being Out of Stock?

A backorder is an order accepted for a product that is temporarily out of stock, to be filled once new inventory arrives, instead of being cancelled or refused. Being "out of stock" is just a fact about your shelf: zero units on hand. A backorder is a decision about what to do with that fact — you keep the sale open and set an expectation, rather than turning the customer away or, worse, letting the register sell a unit that doesn't exist.

The two get confused because most POS systems handle the first fine and the second badly. Stock hits zero, and then either the sale is blocked outright, or — if nobody caught it — the system lets on-hand go negative and nobody notices until a stock count comes up short with no explanation.

Should You Let Customers Order Items You Don't Have Yet?

Backorders make sense for some categories and actively hurt you in others. Before you turn on backorder selling anywhere — in-store, online, or on a marketplace — check the item against these criteria:

• Lead time is short and reliable. If a vendor ships in 3-10 days, a backorder is a minor delay. If lead time is unpredictable or measured in months, you're setting up a complaint.
• The item isn't a cheap, easily substituted impulse buy. Customers will backorder a couch or a specific tool. They won't wait a week for a candle they can get at the store next door.
• You can quote a real date, not a guess. "We'll let you know" loses less trust than a date you miss twice.
• The margin covers the extra handling. Backorders take a follow-up call or text, a note in the system, and sometimes a partial payment to process — that's staff time you should price in.
• A deposit or prepayment is realistic to collect, especially on special orders or big-ticket items like furniture.

How Do You Track What's Owed Without Losing Count of Real Stock?

This is where most spreadsheets and light POS systems fall apart. The fix isn't complicated, but it has to be deliberate: on-hand should always reflect what's physically in the building, and "owed" quantity should live as its own number. The moment you let a sale push on-hand below zero to represent a backorder, your inventory reports start lying — and every other channel selling from that same count (your storefront, your online store, Amazon, eBay) can now oversell it too.

The concept that keeps this straight is available-to-promise (ATP): on-hand minus what's already committed to open orders. If you have 4 units on hand and 6 are committed to backorders, your ATP is negative 2 — which tells you exactly how many more you need before you can promise a new customer anything. ATP is the number a register or storefront should check before accepting a sale, not raw on-hand.

For each backorder, track at minimum:

• Customer name and contact info
• Item, variant, and quantity owed
• Date the order was taken and any deposit collected
• Expected fulfillment date (and who quoted it)
• Which purchase order, if any, is meant to cover it

If you're still doing this on a sticky note or a side spreadsheet, it's worth reading through reorder points and par levels — the same discipline that prevents stockouts is what prevents backorders from turning into a mess.

Should Out-of-Stock Items Be Hidden or Marked as Backorder Online?

There's no single right answer, but there's a wrong way to decide it: by accident, item by item, whenever a customer complains. Set a rule per category instead:

• Hide it when the item is seasonal, discontinued, or the restock date is genuinely unknown — a live backorder with no ship date just generates support tickets.
• Show it as backorderable with a date when the item is core to your assortment, restocks reliably, and customers are used to waiting for it (special orders, made-to-order goods, high-demand releases).
• Leave it live but capped when you have some stock left in another location — this is really a transfer decision, not a backorder one; see multi-location inventory without spreadsheets.
• Always show expected date and update it — a stale "ships in 2 weeks" that's been on the page for two months is worse for trust than hiding the item.

Whatever you choose, the online listing has to check the same stock number the register uses. If your storefront and your POS keep separate counts, you'll end up promising units that a walk-in customer just bought.

How Do You Turn a Backorder Into a Purchase Order?

A backorder that never becomes a purchase order is just a promise sitting in a drawer. The process should be routine, not reactive:

• 1. Set a reorder point on the item so a shortfall shows up before you're already at zero with orders stacking up.
• 2. When on-hand drops below that point — or you've already sold more than you have — create a purchase order sized to cover both the normal restock and every unit currently owed.
• 3. Receive the PO against actual delivered quantities, since partial shipments from vendors are common, not the exception.
• 4. Allocate received stock to the oldest backorders first, so the customer who waited longest gets filled first — not whoever happens to call in that day.
• 5. Notify the customer and close the order out of your "owed" list the moment it's fulfilled, so the number stays honest.

If you want the receiving side of this covered step by step — partial deliveries, vendor bills, cost discrepancies — that's a separate discipline worth getting right on its own.

What Happens When You Oversell an Item You Only Have One Of?

Single-unit items — a one-off antique, a used instrument, a floor-model piece of furniture — are where backorders turn into real problems fastest, because there's no partial fix. If that one unit sells in-store and on your website in the same afternoon because the two aren't reading the same stock number, someone gets a refund and an apology instead of the product they bought.

The same risk shows up across marketplaces. If you list a unique item on Amazon and eBay separately without a shared count, you can sell it twice before either platform knows the other made a sale — which is exactly the kind of overselling that damages a seller account on marketplaces that track order defect rates closely. The fix is structural: sell everything, everywhere, from one inventory count, not a reconciliation habit you have to remember to run.

How Does Retailer OS Handle Backorders?

Retailer OS doesn't bolt a separate "backorder module" onto the side of your inventory — it handles backorders because the underlying pieces already live in one shared ledger:

• A per-item, per-location stock ledger. Every sale, receipt, transfer, and adjustment writes a movement row, so on-hand reflects what's actually in the building, at each store, warehouse, or van, on the multi-location retail management side of the system.
• Available-to-promise on the same catalog. Because the register, online store, and any Amazon or eBay listings read from that one inventory count, a unique item can't be sold twice by different channels at once — see selling on Amazon, eBay, and in-store from one inventory.
• Reorder points and reorder alerts. Set a reorder point per item, and it surfaces in alerts before — or as soon as — it's oversold, instead of you finding out from a customer.
• AI-assisted reorder suggestions on an AI plan (from $19.99/month) help flag what and how much to reorder based on demand, though you still create and approve the purchase order.
• Purchase orders and receiving to close the gap — receive against what actually shows up, including partial deliveries, and the ledger updates the moment stock lands.

None of this requires a second spreadsheet to track what's owed, because "owed" is really just the difference between what's committed and what's on hand — visible in the same inventory visibility view you already use to run the store. Retailer OS is priced per store at $99.99/month plus $9.99/month per user seat; the online store and Amazon/eBay channels that share this inventory are paid add-ons at $99.99/month each. See the full breakdown on pricing.