How sync works

Updated 17 September 2026

Qantory keeps one shared quantity per product and location for the whole group. Every store is equal: there is no “source” store that must be edited first.

What moves between stores

Any change to available stock in any store of the group: an order, a refund or restock, a manual adjustment, a transfer or an import.
Only the available quantity of confirmed products at the shared stock locations. Prices, product details and orders are never copied or changed.

What happens on a change

Shopify tells Qantory that the quantity changed in one store.
Qantory updates the shared quantity for the group, one change at a time per product and location.
Qantory updates the same product in the other stores. Each update only applies if the store still holds the quantity Qantory last saw there; if something changed in the meantime, Qantory reads it first instead of overwriting it.
When Shopify confirms the update, Qantory recognises it as its own and does not send it back — no loops between stores.

Oversell protection

When two stores sell the same product at the same moment, their updates can cross. Qantory settles the conflict with the group’s stock update mode instead of letting the last message win. Every conflict is recorded.

Stock update modes

Choose the mode in the group’s Settings tab.

Mode	What it does	Best for
Prevent overselling (default)	Sales and restocks sync normally. If two stores change the same product at the same moment, the lower quantity wins, so no store sells stock it does not have.	Most merchants.
Main store controls restocks	Only the main store can raise stock. Sales in any store still sync everywhere; a restock entered in another store is held for review.	One warehouse store that receives goods, other stores that only sell.
Accept all Shopify stock changes	Every store can raise or lower stock and the last change wins, even when stores disagree.	Only when every store is a trusted source. A wrong manual edit in one store is copied to the others.

How fast is it?

Usually a few seconds. Shopify can occasionally delay its notifications; Qantory handles late and repeated notifications safely, so a delay never applies an old quantity over a newer one.

Where to see what happened

Activity tab of a group: every change received and every update sent.
Inventory tab: the shared quantity and each store’s quantity side by side.
Issues: anything that needs your attention, with the next step.