Suppliers over-ship, throw in samples, and send things you did not order. Stockroom records what actually turned up rather than forcing the delivery to match the paperwork, so you can receive the whole box and move on.
Counting more than is outstanding
Just count it. On the Receive stock card you can take a line past what is outstanding, by scanning or by typing the quantity, both in the app and on POS.
The status column beside each line tells you where the count stands:
Complete - the count matches what was outstanding.
Over by 3 - you have counted three more than the order had left.
Not ordered - this item was not on the order at all.
3 of 12 - a part count, still short.
Rows you have not touched stay blank on purpose, so your eye only catches what is decided or wrong.
The purchase order's ordered quantity never changes. The order is the agreement you made with your supplier; the receipt is what arrived. So receiving extra does not rewrite the order, and it does not change the PO total or what you owe.
Something that was not on the order
Scan it. If nothing on the delivery matches, Stockroom tells you the code did not match and offers Add to receipt. The item joins the receipt as a line that was ordered zero, so every unit of it counts as extra. Its cost pre-fills from the product and you can edit it.
Unmatched scans build up as a list with a count of how many times each code was scanned, so a handful of surprises in one delivery do not overwrite each other.
If the barcode is not on any product in Stockroom at all, there is nothing to receive it as - check the label, or add the product in Shopify first and sync.
After your first scan of a session a Sound on / Sound off toggle appears: distinct cues for a normal count, going over, and a scan that matched nothing. The choice is remembered on that device.
What reaches Shopify
Everything that arrived becomes sellable. Units you had ordered move from incoming to available, the way they always do. Extra units go straight to available, because they were never counted as incoming in the first place.
Deliveries that arrive late
If you used Cancel remaining or closed the order and the goods turn up afterwards, receive them anyway - a late delivery is recorded rather than refused.
Rejects stay capped
You can only reject up to what was outstanding. A supplier cannot owe you for more than you ordered, so the reject column stops there even when the count goes over.
Two things to watch
Landed cost is shared out on the ordered quantities. Extra units carry the same freight and duty rate per unit as the units beside them, which means the total allocated charge sits slightly above the charge you actually entered - by the extra quantity times the per-unit rate. That is deliberate. A small, predictable drift is better than one unit costing a different amount from an identical unit in the same box.
Extra units get no label allowance. The number of labels a receipt offers is based on the ordered quantity, so labels for the extras are not counted in. Print those from the product, or from a standalone label print. Nothing breaks - there are simply fewer labels than units.
Good to know
This works the same on Shopify POS as it does in the app, and no POS Pro subscription is required.
Scanning fills every line that still has room across the order (and any orders included with it) before any scan is allowed to count over, so a scan never reports an over-delivery while a sibling line is still short.
If the over-delivery is going back to the supplier, that is a supplier return rather than an edit to the receipt. See Return stock to a supplier.
If the delivery was recorded wrongly rather than genuinely over-delivered, undo the receipt instead. See Receiving Inventory Against a Purchase Order.