When a replacement costs a different amount from the original item, money has to move. Tacey never guesses the amount and never moves money the customer has not seen. Every figure comes from Shopify's own calculation, and every swap is written to your Ledger.
Same price
The swap is made, the old item is restocked, and no money moves in either direction.
The replacement costs more
On the confirm step the customer sees Payment due and the amount Shopify calculated for the difference.
They tap Confirm & pay. The swap is made on the order.
Pay now opens Shopify's own payment page for exactly that amount.
Until they pay, the order has a hold on fulfilment and the `tacey-payment-owed` tag, so it does not ship unpaid.
When the payment arrives, the hold is released and the tag is removed.
Tax on stores that add tax at checkout. Shopify only adds tax to the new item once the swap is saved, so on a store that charges tax on top of prices, the confirm step can show the difference "+ tax". Shopify's payment page always shows the exact total, including tax, before the customer pays. Your Ledger records the final figure Shopify charged.
If the customer never pays, the hold is released after the wait set in Change product options (Hours to wait for payment on an added item, 24 hours by default), so the order is not stuck forever. The replacement stays on the order and the balance stays owed in Shopify, so check the order and your Ledger and follow up with the customer.
The replacement costs less
On the confirm step the customer sees that they are owed money back to their original payment method.
They confirm. The swap is made on the order. No refund is sent at this moment.
Tacey waits until the customer has stopped making changes to the order for 15 minutes. This way, if they also add something, the two changes can net against each other instead of causing a refund and then a new charge.
Tacey then reads the amount Shopify says is owed, and: - If Refund customers automatically is off (the default): the refund waits for you. The order page shows "A refund is waiting for your approval". Click Approve refund to send Shopify's current owed amount back to the original payment method, once. - If Refund customers automatically is on: Tacey sends the refund itself, normally 15 to 30 minutes after the customer's last change.
If the amount owed has dropped to zero in the meantime (for example the customer added something), no refund is sent and the Ledger records why. If you already refunded by hand in Shopify, Tacey sees it and does not refund twice.
Turning automatic refunds on or off
In Tacey, open Editing Tools, then Global settings.
Under Refunds, turn Refund customers automatically on or off.
Save.
This same switch covers refunds from a customer's applied discount.
Limiting how far the price can move
Most a replacement's price can differ, per item caps the difference in either direction. At 0 (the default) there is no limit. With a cap set, a replacement whose price differs by more than that per item is refused before anything changes on the order.
What this does NOT do
It does not charge a card by itself. The customer always pays through Shopify's payment page after seeing the amount.
It does not refund to store credit. A cheaper replacement is refunded to the original payment method.
It does not send a refund without your approval, unless you turned on Refund customers automatically.
Related