Exchanges in Rundoo happen inside a single transaction — put a negative-quantity line for what's coming back and a positive-quantity line for what's going out, and the cart nets the two.

In the POS mode, open the cart on the left — same place you ring up any other sale.

How an exchange works

There's no dedicated Exchange button. The move is to mix quantities on one cart:

• One line with a negative quantity — the item the customer is returning. Set the stepper to -1 (or whatever count is coming back). Rundoo treats the line as a refund — it credits the customer for the extended price and puts the stock back on hand.
• One line with a positive quantity — the replacement item going out. Set the stepper to 1 (or whatever they're leaving with). Rundoo treats the line as a sale — it charges the customer and depletes stock.

The cart totals net the two lines. Subtotal, tax, and total at the bottom reflect the difference, not the gross of either line. Pick a tender, take payment (or refund) for the net, and you're done — one receipt, one transaction, one line of history.

Even swaps

When the two lines match in extended price — a gallon of one color for a gallon of another color at the same price, a tape swap for a same-priced tape — the cart totals to $0.00. Close it out with a $0 tender and the customer walks with the replacement item without paying anything extra or getting cash back.

This is the cleanest scenario for exchanges and the one you'll see most often: a contractor grabbed the wrong color or size and wants the right one.

Unequal values

When the lines don't match in price, the net drives the remainder:

• Replacement costs more — the cart total is positive and the customer owes the difference. Pick whatever tender they want to use (Cash, Card, Charge account) and take payment for the net. See Tender methods for what each option does.
• Replacement costs less — the cart total is negative and Rundoo owes the customer. Pick a refund tender — cash back, refund to card, credit their Charge account balance, or park it on Customer credit for next time — and the refund processes against the net.

Tax calculates on each line individually, so a higher-tax replacement swapping in for a lower-tax return will shift the net by more than the pre-tax price difference. The totals at the bottom of the cart are the truth.

When to return + ring up separately instead

The mixed-quantity flow is the right default, but it doesn't fit every case. Run the refund and the new sale as two separate transactions when the swap crosses customers (one person's return funding a different person's purchase), when a receipt-linked refund is required (loading the original sale from the customer's history and pulling specific lines back), or when the customer wants their money back first and decides on the replacement later. See Returns for the receipt-linked flow and refund tender mechanics.

Recommended Rundocs

• Sales — the base cart flow exchanges build on.