When something sells

When CellerHub imports a sale from a channel, it does two things, in order:

1. Deducts the stock that sold, once, from the product’s on-hand quantity.
2. Pushes the new quantity to every other channel that also carries that product, so a sale on one marketplace is reflected everywhere else without you touching anything.

It can’t double-count a sale

Every order is matched to the specific sale it came from. If a sync runs again and sees the same order — because it polled twice, or a retry happened — your stock is not deducted a second time for it.

Stock never goes negative

If two channels both sell what looks like your last one at nearly the same time, the second deduction is clamped at zero rather than taking your stock negative.

Cancellations and refunds give stock back

If an order is cancelled or refunded, CellerHub returns the units it took and re-syncs your other channels — with one exception: an order from before you connected a channel that was already fulfilled (see Your first sync) never had stock deducted from it in the first place, so cancelling or refunding it doesn’t hand stock back either. There’s nothing to give back for a sale CellerHub never subtracted.

A pending order reserves stock instead

An order that hasn’t shipped yet — still pending or just paid — reserves its stock rather than deducting it outright. You’ll see this as “reserved” quantity on the product’s inventory rows (see Stock adjustments and warehouses). The stock is set aside for that buyer, but only actually deducted from your on-hand count once the sale is confirmed.