Stock and Inventory
How stock is counted, selling from several locations, the rollup that surprises people, and backorders.
Stock lives on the product, or on each variant when a product has them. It is the number that decides whether something can be bought.
Tracking, or Not
Track inventory on means the shop counts down with each sale and stops selling at zero.
Off means it sells forever. That is right for a download, a service, a made to order item or a membership, and wrong for anything on a shelf.
Turning tracking off does not zero the count
The number stays where it was and is simply ignored. Turning tracking back on later resumes from that old figure, which is rarely what you want. Check the number when you switch it back on.
When Stock Comes Down
At the point the order is placed, not when it is paid or shipped.
That is deliberate: it stops two people buying the last one in the minute between ordering and paying.
When Stock Goes Back
Two things return it, both automatically.
A payment that fails. The order stays in your list with its payment marked failed, and the goods go back on the shelf immediately, because an order nobody paid for is not going to ship.
Cancelling an order. The cancel dialogue offers to restock and does so by default. Untick it when the goods are genuinely gone: a parcel already posted, or something damaged in packing.
In both cases the stock goes back the way it was taken, to the right variant and the right location, and the movement appears in the product's inventory history marked as a restock.
An order that is placed and never paid is still holding stock
An unpaid cheque or purchase order has taken the goods, which is correct, because you are going to ship them. One that is never going to be paid should be cancelled rather than left sitting, or it holds stock indefinitely. The Invoice Aging Report is where you find them.
Backorders
Allow backorders lets a product keep selling past zero.
Use it when you genuinely can supply, and say so on the product, because a customer who discovers a two week wait after paying is a customer who asks for a refund. The delivery estimate on your product page is doing that job if you keep it current.
Low Stock Warnings
Low stock threshold is the number at or below which a product appears in the low stock figure on the dashboard and in the alerts.
A product with no threshold never warns you about anything. If your dashboard says zero low stock and you are certain that is wrong, the thresholds are the thing to check rather than the stock.
Alerts go to one address, set under Settings, Notifications. See the notification settings for who receives them.
Several Locations
A shop holding stock in more than one place can record it per location rather than as one number: a shop and a warehouse, two warehouses, or a separate pool of damaged copies.
The product's overall figure then becomes the sum of its locations.
This is the thing that catches people out
Saving any per location quantity recalculates the product's total as the sum of the locations. If you had typed a different number into the overall field a moment earlier, it is replaced without warning. Decide which way you are working, per product or per location, and stay with it.
An order can be fulfilled from a particular location, which is how a second warehouse works, and the shipping origin attached to that location is what carriers quote from.
Damaged or Second Quality Stock
A product can carry a count of damaged copies and a damaged price, sold from the same listing. They draw from their own pool rather than your good stock, so selling a damaged copy does not reduce what you can sell at full price.
That is how shelf worn, hurt or second quality goods are sold without creating a duplicate product for each one.
Adjusting Stock
Edit the figure on the product, or on the variant, or per location. Every change is recorded in the product's inventory history with who did it and why, which is what you consult when a count has drifted.
For a large correction, the import covered in Importing and Exporting is faster and leaves the same trail.
The Inventory Report
Shows what is on the shelf, what is low and what is out, across the catalogue.
Run it before a sale rather than after. The most expensive stock problem is discovering on the second day of a promotion that the thing being promoted ran out on the first.