A backorder is an order you accept for a product that is temporarily out of stock, and ship once new stock arrives. The product page stays buyable, the customer pays or commits now, and you promise a later ship date. That is the difference with out of stock, where the buy button is off, and with a preorder, which is for a product that has not been released yet.
Backorders keep revenue coming in while a delivery is on its way, but they only work when every channel says the same thing: the shop shows a realistic date, the feed sends the right availability value, and you actually ship inside the time you promised. Below are the definitions, the exact settings in Shopify, WooCommerce and Magento 2, the Google Merchant Center values, the EU delivery rule and the wording that keeps customers informed.
Backorder vs out of stock vs preorder vs supplier lead time
Four situations look alike from the outside (no item on your shelf) but need different settings, different page copy and different feed values. Google's availability attribute draws the line clearly: preorder is only for new products that have not been released, and an existing product that will be back in stock, and that you accept orders for, is a backorder.
Four stock situations compared
| Backorder | Yes | No, restock expected | Expected ship date | backorder + availability_date | A desk lamp sold out, next container lands in three weeks |
|---|---|---|---|---|---|
| Out of stock | No | No | Sold out, buy button off | out_of_stock | A sofa fabric with no confirmed restock |
| Preorder | Yes | No, not released yet | Release or ship date | preorder + availability_date | Next season's running shoe, launching in March |
| Supplier ships (dropship) | Yes | Not with you, at the supplier | Longer delivery time | in_stock, if it ships in good time | A garden bench shipped from the supplier's warehouse in five working days |
The supplier case is the one teams most often label wrong. If a supplier holds stock and ships within a known time, the product is in stock with a longer delivery time, not on backorder. Calling it a backorder scares buyers off for no reason; calling a genuinely empty product in stock leads to cancellations.
Which stock status fits the product
When to accept backorders and when to switch them off
Backorders are a promise. They make sense when you can keep it and backfire when you cannot. Use these tests per product, not per store.
- Accept them when a purchase order is confirmed with a delivery date, the supplier has a track record of hitting it, and the product is not tied to a date the customer cares about.
- Cap them when restock quantity is known: if 200 lamps are on the way, stop accepting backorders at 200, not at infinity.
- Switch them off for gifts in the weeks before a holiday, seasonal items whose season ends before the restock, and anything without a confirmed date. Our Black Friday checklist includes a stock and availability check for the peak weeks.
- Be careful on marketplaces. Most marketplaces score sellers on late shipments and cancellations, so a missed backorder date costs more there than in your own shop. Check the seller standards of each marketplace before you allow backorders on listings that sell there.
Shopify: the Continue selling when out of stock setting
Shopify has no separate backorder status. You allow it per product or variant, and the product keeps selling when its quantity reaches zero. According to the Shopify Help Center:
- Open the product or variant in the Shopify admin.
- In the Inventory section, make sure Inventory tracked is on. The overselling option only appears when it is.
- Select Continue selling when out of stock and save.
Two details matter. The setting does not apply to Shopify POS orders, and with several locations, inventory is assigned per location: an item at zero in the location that fulfills online orders shows as out of stock online even if another location has units. Shopify also does not add a ship date for you, so the date has to come from your theme, an app or the product description.
WooCommerce: Allow back orders and its three options
WooCommerce has the most explicit backorder settings of the three platforms. In the product's Inventory section, the WooCommerce documentation describes two routes:
- With Stock management checked: you enter a Quantity and choose under Allow back orders? between Do not allow, Allow, but notify customer (a backorder notice on the product page, in the block-based cart and checkout, in the order and in customer emails) and Allow (the product looks no different from an in-stock item).
- Without Stock management: you set Stock status by hand to In Stock, Out of stock or On back order. On back order shows a notice on the product page only, not in the cart, order or emails.
For most stores, Allow, but notify customer is the honest default: the customer sees the delay before paying and finds it again in the confirmation email. Plain Allow hides the delay, which is fine only when restock is days away.
Magento 2: Backorders and the Out-of-Stock Threshold
In Adobe Commerce and Magento Open Source you set backorders globally and override them per product. Globally, go to Stores > Settings > Configuration > Catalog > Inventory > Product Stock Options. The Adobe Commerce documentation lists three values for Backorders:
- No Backorders: no orders once the product is out of stock.
- Allow Qty Below 0: orders continue and the quantity goes negative.
- Allow Qty Below 0 and Notify Customer: the same, plus a message telling the customer the order can still be placed.
The Out-of-Stock Threshold is where you cap backorders. With backorders on, 0 allows unlimited backorders, and a negative value sets the limit: -50 accepts up to 50 units below zero. Adobe also notes that the product must have the In Stock status when you enable backorders, and that backorder payments are captured immediately while shipping stays on hold until stock arrives.
Google Merchant Center availability values and availability_date
Google accepts four availability values for ordinary products: in_stock, out_of_stock, preorder and backorder (plus build_to_order for vehicle ads). When you send backorder or preorder, Google asks for the availability_date attribute: the day the product will ship.
- Format: ISO 8601 with time and time zone, for example 2026-12-04T09:00+0100. Without a time and zone, Google assumes midnight UTC.
- One date, no range: if you only have an estimate, send your best estimate (Google suggests up to a year ahead) and update it when the date firms up.
- Same date on the page: Google asks for the expected ship date to be visible on the landing page as well. Without an exact date, an estimated date is allowed (Google's example is a month and year, such as "December 2026").
- Consistency across all sources: availability has to match between the feed, the landing page, structured data and checkout, or Google disapproves the product.
That last rule is where backorders cause trouble: the shop allows backorders, but the feed still says out_of_stock, or the feed says backorder while the page shows no date. Our guide to the mismatched availability error walks through the fixes. Also keep in mind that the backorder value is Google's; other feed channels use their own vocabulary for the same situation.
EU delivery rules for backordered goods
For sales to consumers in the EU, the Consumer Rights Directive sets the baseline. Article 18 of Directive 2011/83/EU says that, unless the parties agreed otherwise on the time of delivery, the trader must deliver without undue delay and no later than 30 days after the contract is concluded. Article 6 also requires you to tell the customer, before they are bound, the time by which you undertake to deliver.
- Show the date before checkout. A backorder date stated clearly on the product page and in the cart is how a later delivery time becomes part of the agreement.
- If you miss the date, the customer can give you an additional, reasonable period. If you miss that too, they can terminate the contract.
- If the date was essential (the customer said so before ordering, or it obviously was, such as a costume for a set date), they can terminate immediately.
- Refund without undue delay on termination: all sums paid under the contract.
Backorder messages for the product page, cart and emails
Customers accept a wait when they know about it before paying. They cancel, complain or leave a bad review when they find out afterwards. Write the message once and reuse it everywhere the product appears.
- Product page, near the buy button: "On backorder. Order now and we ship around 4 December." Put the date next to the button, not in the description tabs.
- Button label: "Order now, ships in 3 weeks" instead of an unchanged "Add to cart".
- Cart and checkout: repeat the date per line, and say what happens to a mixed order (ship together or in parts).
- Order confirmation: the expected ship date, and how to cancel if the customer changes their mind.
- When the date slips: email before the old date passes, with the new date and a one-click cancel option.
Before you switch backorders on for a product
Stock fields that have to agree across every channel
Behind every backorder sit a few product fields: the quantity, a stock status, whether backorders are allowed, and the expected date. Trouble starts when they contradict each other, such as status on backorder while backorders are not allowed, or quantity 40 while the status says out of stock. Each channel reads a different combination, so one wrong field shows up as a different error on each one. Our dictionary entry on stock availability covers the terms, and the stockout loss calculator estimates what an empty shelf costs when you decide against backorders.
Take a black desk lamp, SKU LAMP-DSK-BLK, sold out with 120 units arriving on 4 December. Consistent data for that one product looks like this:
- Product record: quantity 0, status on backorder, backorders allowed, with a cap of 120 units.
- Shopify: Inventory tracked on and Continue selling when out of stock selected.
- WooCommerce: Stock management on, Allow back orders? set to Allow, but notify customer.
- Magento 2: Backorders set to Allow Qty Below 0 and Notify Customer, Out-of-Stock Threshold -120.
- Google feed: availability backorder, availability_date 2026-12-04T09:00+0100.
- Product page and cart: "Ships around 4 December" next to the buy button.
- When the container lands: quantity becomes 120 minus the units already backordered, status goes back to in stock, backorders go off and the feed returns to in_stock.
WISEPIM is not an inventory system or order management system: it does not take orders or count stock down as they come in. It does keep stock fields on the product record (quantity, a stock status of in stock, out of stock or on backorder, and whether backorders are allowed) and sends them with the rest of the product data. On export, the backorders setting becomes Shopify's continue or deny selling policy. For WooCommerce and Magento, WISEPIM sends the plain allow option (Allow, and Allow Qty Below 0), not the notify variants, so a notify setting you chose in the shop is replaced on the next export. Feed Hub sends backorder to a Google Shopping feed for every product that has backorders allowed, even while units are still in stock, and maps it to each other channel's own term; switch backorders off once the restock lands. The direct Google Merchant Center connection works from quantity alone and sends in stock or out of stock. WISEPIM has no built-in expected ship date field: keep the date in a custom attribute and map it to availability_date in the feed's field mapping. A bulk action in bulk operations sets the stock status for a whole selection, and the quality checks flag a product marked on backorder while backorders are not allowed. The marketplace stock sync page shows how stock travels with each export, and platform sync covers the shop connections.

