Open the returns screen
Press F9, or choose Returns. The screen asks for the sale you are refunding.
Find the original sale
Scan the barcode printed under the totals on the customer's receipt and the sale opens. You can also search by receipt number, by date, or from the list of the day's sales.
A sale made while the shop's internet was down is found the same way. The shop's own server holds every sale, so nothing depends on a connection to look up a receipt.
Refund the whole sale or part of it
Choose the lines being returned and the quantity of each. A customer bringing back one of three shirts refunds one shirt, not the sale.
A line that has already been refunded cannot be refunded twice, and the till will not let you past it.
Where the money goes
A refund goes back the way it came. If the sale was paid half in cash and half by card, the refund is bounded by what each method actually contributed, less anything already returned against it — including a refund another till committed a minute ago.
On a split payment, the non-cash part is returned first. A refund that does not fit the original payment is refused rather than made up out of the drawer.
Restock or write off
Each returned line is either put back on the shelf or written off, with a reason recorded against it. The choice is per line, because a customer returning two things can quite normally have one that is resellable and one that is not.
A written-off return still records the goods coming back, so the write-off is a figure your damage report can read rather than a gap in the stock ledger.
Refund to a different method
Refunding to something other than the original payment is possible, needs a manager, and requires a stated reason that is recorded on the refund. It is deliberately the harder path.
Every refund has a name on it
A refund needs a supervisor's PIN. Cashiers can sell without being able to refund, which is the single most useful control on a shop till.
The refund, its lines, its reasons and the person who approved it all go into the shop's records and into the discount and refund reporting.
Cancel a sale before payment
Clear the cart with Shift+Del and confirm. Nothing has been committed yet, so nothing needs refunding — but the void is recorded, because a cart cleared repeatedly at the same till is worth knowing about.
Cancel a paid sale in the same shift
A sale paid by mistake a minute ago is cancelled rather than refunded, which keeps it out of your refund figures. It is a manager action and is logged.
Exchanges
An exchange is a return and a new sale together: return the lines coming back, then build the new cart with the credit already applied. The customer pays the difference, or takes it back, in one movement at the counter.