Why Shopify Inventory Goes Negative (and How to Fix It)

Why is my Shopify inventory negative?

These are the usual causes, roughly in order of how often they come up:

• Continue selling when out of stock is turned on for the product. Customers can keep buying after the count reaches zero, and every sale takes it further below. Shopify explains the setting in its guide to selling when out of stock (opens in a new tab).
• A sale in your shop through Shopify POS. That setting doesn’t apply to POS. Staff get a warning, but they can still sell an item that shows zero.
• The wrong location. If you stock more than one location, an online order takes units from the location it’s assigned to. When no single location can cover it, Shopify can split the order or let the highest-priority location oversell. That location goes negative while another one still has stock. Shopify’s page on how orders are assigned to locations (opens in a new tab) covers the rules.
• An app or import overwrote the count. A marketplace sync, a warehouse app or a CSV import can set the count from an older number while orders keep coming in.
• The count was already wrong. Damaged stock nobody removed, a delivery received twice, or a miscounted shelf. The sale only makes the old error visible.

How to fix negative inventory in Shopify

1. Find the items below zero. Go to Products, then Inventory, and pick the location. Look for anything with a minus in the Available column. Check each location separately, because the problem is often in only one of them.
2. See what happened. Open the product, click the variant, and click View adjustment history. It lists every change with the date, what caused it and who or which app made it. Shopify describes the columns in its adjustment history guide (opens in a new tab). That usually tells you which of the causes above it was.
3. Check for orders still waiting on the item. A negative number often means customers paid for units you don’t have. Decide for each one: restock and ship late, offer a swap, or cancel and refund. Our guide to paid orders that haven’t shipped shows how to list them, and our cancellation guide covers the last option.
4. Count the shelf, then set the number. In Products, then Inventory, click the Available quantity, choose Set to, and enter what you actually have. Add a reason such as Count so the history makes sense later. Shopify walks through this in adjusting inventory quantities (opens in a new tab).

Don’t just set the count to zero to make the minus go away. If the shelf really is empty and there are open orders, zero hides the fact that you still owe those customers something.

How to stop overselling in Shopify

Turn off Continue selling when out of stock on products where you don’t mean to take preorders or backorders. If you sell in person, make sure staff know the POS warning means the item isn’t there. With more than one location, check that your order routing sends orders to the location that actually holds the stock. And if an app syncs inventory, make sure only one system is allowed to set the counts.

It also helps to know what each inventory number means. Shopify’s page on inventory states (opens in a new tab) explains available, on hand, committed and incoming.

Spot negative stock as soon as it happens

Out of the box, Shopify doesn’t alert you when a count drops below zero. Often the first sign is a customer asking where their order is.

Efficiencia’s Today screen includes a negative stock check in its Orders that need you section. When an item’s available count drops below zero at one of your active locations, it shows up in the list with the SKU, the location and the count. Each location is checked on its own, so stock elsewhere doesn’t hide the problem. You correct the count in Shopify and the item clears from the list. The check reacts to stock changes, so an item that was already negative before you connected your store shows up the next time its stock changes.

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